Sensors

Research

Jump to: Review

14 pages, 7333 KiB

Open AccessArticle

Plasmonic Refractive Index Sensor with High Figure of Merit Based on Concentric-Rings Resonator

by Zhaojian Zhang, Junbo Yang, Xin He, Jingjing Zhang, Jie Huang, Dingbo Chen and Yunxin Han

Sensors 2018, 18(1), 116; https://doi.org/10.3390/s18010116 - 4 Jan 2018

Cited by 168 | Viewed by 7904

Abstract

A plasmonic refractive index (RI) sensor based on metal-insulator-metal (MIM) waveguide coupled with concentric double rings resonator (CDRR) is proposed and investigated numerically. Utilizing the novel supermodes of the CDRR, the FWHM of the resonant wavelength can be modulated, and a sensitivity of [...] Read more.

A plasmonic refractive index (RI) sensor based on metal-insulator-metal (MIM) waveguide coupled with concentric double rings resonator (CDRR) is proposed and investigated numerically. Utilizing the novel supermodes of the CDRR, the FWHM of the resonant wavelength can be modulated, and a sensitivity of 1060 nm/RIU with high figure of merit (FOM) 203.8 is realized in the near-infrared region. The unordinary modes, as well as the influence of structure parameters on the sensing performance, are also discussed. Such plasmonic sensor with simple framework and high optical resolution could be applied to on-chip sensing systems and integrated optical circuits. Besides, the special cases of bio-sensing and triple rings are also discussed. Full article

(This article belongs to the Special Issue Surface Plasmon Resonance Sensing)

► Show Figures

Figure 1

1568 KiB

Open AccessArticle

Quantitative and Sensitive Detection of Chloramphenicol by Surface-Enhanced Raman Scattering

by Yufeng Ding, Xin Zhang, Hongjun Yin, Qingyun Meng, Yongmei Zhao, Luo Liu, Zhenglong Wu and Haijun Xu

Sensors 2017, 17(12), 2962; https://doi.org/10.3390/s17122962 - 20 Dec 2017

Cited by 31 | Viewed by 5673

Abstract

We used surface-enhanced Raman scattering (SERS) for the quantitative and sensitive detection of chloramphenicol (CAP). Using 30 nm colloidal Au nanoparticles (NPs), a low detection limit for CAP of 10⁻⁸ M was obtained. The characteristic Raman peak of CAP centered at 1344 [...] Read more.

We used surface-enhanced Raman scattering (SERS) for the quantitative and sensitive detection of chloramphenicol (CAP). Using 30 nm colloidal Au nanoparticles (NPs), a low detection limit for CAP of 10⁻⁸ M was obtained. The characteristic Raman peak of CAP centered at 1344 cm⁻¹ was used for the rapid quantitative detection of CAP in three different types of CAP eye drops, and the accuracy of the measurement result was verified by high-performance liquid chromatography (HPLC). The experimental results reveal that the SERS technique based on colloidal Au NPs is accurate and sensitive, and can be used for the rapid detection of various antibiotics. Full article

(This article belongs to the Special Issue Surface Plasmon Resonance Sensing)

► Show Figures

Graphical abstract

3235 KiB

Open AccessArticle

A Low-Cost and Portable Dual-Channel Fiber Optic Surface Plasmon Resonance System

by Qiang Liu, Yun Liu, Shimeng Chen, Fang Wang and Wei Peng

Sensors 2017, 17(12), 2797; https://doi.org/10.3390/s17122797 - 4 Dec 2017

Cited by 21 | Viewed by 6665

Abstract

A miniaturization and integration dual-channel fiber optic surface plasmon resonance (SPR) system was proposed and demonstrated in this paper. We used a yellow light-emitting diode (LED, peak wavelength 595 nm) and built-in web camera as a light source and detector, respectively. Except for [...] Read more.

A miniaturization and integration dual-channel fiber optic surface plasmon resonance (SPR) system was proposed and demonstrated in this paper. We used a yellow light-emitting diode (LED, peak wavelength 595 nm) and built-in web camera as a light source and detector, respectively. Except for the detection channel, one of the sensors was used as a reference channel to compensate nonspecific binding and physical absorption. We packaged the LED and surface plasmon resonance (SPR) sensors together, which are flexible enough to be applied to mobile devices as a compact and portable system. Experimental results show that the normalized intensity shift and refractive index (RI) of the sample have a good linear relationship in the RI range from 1.328 to 1.348. We used this sensor to monitor the reversible, specific interaction between lectin concanavalin A (Con A) and glycoprotein ribonuclease B (RNase B), which demonstrate its capabilities of specific identification and biochemical samples concentration detection. This sensor system has potential applications in various fields, such as medical diagnosis, public health, food safety, and environment monitoring. Full article

(This article belongs to the Special Issue Surface Plasmon Resonance Sensing)

► Show Figures

Figure 1

5250 KiB

Open AccessArticle

A Sensitive and Stable Surface Plasmon Resonance Sensor Based on Monolayer Protected Silver Film

by Guiqiang Wang, Chunnan Wang, Rui Yang, Wenlan Liu and Shuqing Sun

Sensors 2017, 17(12), 2777; https://doi.org/10.3390/s17122777 - 30 Nov 2017

Cited by 71 | Viewed by 6154

Abstract

In this paper, we present a stable silver-based surface plasmon resonance (SPR) sensor using a self-assembled monolayer (SAM) as a protection layer and investigated its efficiency in water and 0.01 M phosphate buffered saline (PBS). By simulation, silver-based SPR sensor has a better [...] Read more.

In this paper, we present a stable silver-based surface plasmon resonance (SPR) sensor using a self-assembled monolayer (SAM) as a protection layer and investigated its efficiency in water and 0.01 M phosphate buffered saline (PBS). By simulation, silver-based SPR sensor has a better performance in field enhancement and penetration depth than that of a gold-based SPR sensor, which are 5 and 1.4 times, respectively. To overcome the instability of the bare silver film and investigate the efficiency of the protected layer, the SAM of 11-mercapto-1-undecanol (MUD) was used as a protection layer. Stability experiment results show that the protected silver film exhibited excellent stability either in pure water or 0.01 M PBS buffer. The sensitivity of the silver-based SPR sensor was calculated to be 127.26 deg/RIU (refractive index unit), measured with different concentrations of NaCl solutions. Further, a very high refractive resolution for the silver-based SPR sensor was found to be 2.207 × 10⁻⁷ RIU, which reaches the theoretical limit in the wavelength of 632.8 nm for a SPR sensor reported in the literature. Using a mixed SAM of 16-mercaptohexadecanoic acid (MHDA) and a MUD layer with a ratio of 1:10, this immunosensor for the rabbit immunoglobulin G (IgG) molecule with a limit of detection as low as 22.516 ng/mL was achieved. Full article

(This article belongs to the Special Issue Surface Plasmon Resonance Sensing)

► Show Figures

Figure 1

428 KiB

Open AccessArticle

Gold Nanoparticles Used as Protein Scavengers Enhance Surface Plasmon Resonance Signal

by Erenildo Ferreira de Macedo, Daniela Maria Ducatti Formaggio, Nivia Salles Santos and Dayane Batista Tada

Sensors 2017, 17(12), 2765; https://doi.org/10.3390/s17122765 - 29 Nov 2017

Cited by 16 | Viewed by 5095

Abstract

Although several researchers had reported on methodologies for surface plasmon resonance (SPR) signal amplification based on the use of nanoparticles (NPs), the majority addressed the sandwich technique and low protein concentration. In this work, a different approach for SPR signal enhancement based on [...] Read more.

Although several researchers had reported on methodologies for surface plasmon resonance (SPR) signal amplification based on the use of nanoparticles (NPs), the majority addressed the sandwich technique and low protein concentration. In this work, a different approach for SPR signal enhancement based on the use of gold NPs was evaluated. The method was used in the detection of two lectins, peanut agglutinin (PNA) and concanavalin A (ConA). Gold NPs were functionalized with antibodies anti-PNA and anti-ConA, and these NPs were used as protein scavengers in a solution. After being incubated with solutions of PNA or ConA, the gold NPs coupled with the collected lectins were injected on the sensor containing the immobilized antibodies. The signal amplification provided by this method was compared to the signal amplification provided by the direct coupling of PNA and ConA to gold NPs. Furthermore, both methods, direct coupling and gold NPs as protein scavengers, were compared to the direct detection of PNA and ConA in solution. Compared to the analysis of free protein, the direct coupling of PNA and ConA to gold NPs resulted in a signal amplification of 10–40-fold and a 13-fold decrease of the limit of detection (LOD), whereas the use of gold NPs as protein scavengers resulted in an SPR signal 40–50-times higher and an LOD 64-times lower. Full article

(This article belongs to the Special Issue Surface Plasmon Resonance Sensing)

► Show Figures

Figure 1

1316 KiB

Open AccessArticle

LSPR Coupling and Distribution of Interparticle Distances between Nanoparticles in Hydrogel on Optical Fiber End Face

by Harald Ian Muri and Dag Roar Hjelme

Sensors 2017, 17(12), 2723; https://doi.org/10.3390/s17122723 - 25 Nov 2017

Cited by 27 | Viewed by 6312

Abstract

We report on a new localized surface plasmon resonance (LSPR)-based optical fiber (OF) architecture with a potential in sensor applications. The LSPR-OF system is fabricated by immobilizing gold nanoparticles (GNPs) in a hydrogel droplet polymerized on the fiber end face. This design has [...] Read more.

We report on a new localized surface plasmon resonance (LSPR)-based optical fiber (OF) architecture with a potential in sensor applications. The LSPR-OF system is fabricated by immobilizing gold nanoparticles (GNPs) in a hydrogel droplet polymerized on the fiber end face. This design has several advantages over earlier designs. It dramatically increase the number nanoparticles (NP) available for sensing, it offers precise control over the NP density, and the NPs are positioned in a true 3D aqueous environment. The OF-hydrogel design is also compatible with low-cost manufacturing. The LSPR-OF platform can measure volumetric changes in a stimuli-responsive hydrogel or measure binding to receptors on the NP surface. It can also be used as a two-parameter sensor by utilizing both effects. We present results from proof-of-concept experiments exploring the properties of LSPR and interparticle distances of the GNP-hydrogel OF design by characterizing the distribution of distances between NPs in the hydrogel, the refractive index of the hydrogel and the LSPR attributes of peak position, amplitude and linewidth for hydrogel deswelling controlled with pH solutions. Full article

(This article belongs to the Special Issue Surface Plasmon Resonance Sensing)

► Show Figures

Figure 1

1136 KiB

Open AccessArticle

Laser-Induced Breakdown Spectroscopy for Rapid Discrimination of Heavy-Metal-Contaminated Seafood Tegillarca granosa

by Guoli Ji, Pengchao Ye, Yijian Shi, Leiming Yuan, Xiaojing Chen, Mingshun Yuan, Dehua Zhu, Xi Chen, Xinyu Hu and Jing Jiang

Sensors 2017, 17(11), 2655; https://doi.org/10.3390/s17112655 - 17 Nov 2017

Cited by 19 | Viewed by 5730

Abstract

Tegillarca granosa samples contaminated artificially by three kinds of toxic heavy metals including zinc (Zn), cadmium (Cd), and lead (Pb) were attempted to be distinguished using laser-induced breakdown spectroscopy (LIBS) technology and pattern recognition methods in this study. The measured spectra were firstly [...] Read more.

Tegillarca granosa samples contaminated artificially by three kinds of toxic heavy metals including zinc (Zn), cadmium (Cd), and lead (Pb) were attempted to be distinguished using laser-induced breakdown spectroscopy (LIBS) technology and pattern recognition methods in this study. The measured spectra were firstly processed by a wavelet transform algorithm (WTA), then the generated characteristic information was subsequently expressed by an information gain algorithm (IGA). As a result, 30 variables obtained were used as input variables for three classifiers: partial least square discriminant analysis (PLS-DA), support vector machine (SVM), and random forest (RF), among which the RF model exhibited the best performance, with 93.3% discrimination accuracy among those classifiers. Besides, the extracted characteristic information was used to reconstruct the original spectra by inverse WTA, and the corresponding attribution of the reconstructed spectra was then discussed. This work indicates that the healthy shellfish samples of Tegillarca granosa could be distinguished from the toxic heavy-metal-contaminated ones by pattern recognition analysis combined with LIBS technology, which only requires minimal pretreatments. Full article

(This article belongs to the Special Issue Surface Plasmon Resonance Sensing)

► Show Figures

Figure 1

3044 KiB

Open AccessArticle

Interaction between Diethyldithiocarbamate and Cu(II) on Gold in Non-Cyanide Wastewater

by Nguyễn Hoàng Ly, Thanh Danh Nguyen, Kyung-Duk Zoh and Sang-Woo Joo

Sensors 2017, 17(11), 2628; https://doi.org/10.3390/s17112628 - 15 Nov 2017

Cited by 18 | Viewed by 7115

Abstract

A surface-enhanced Raman scattering (SERS) detection method for environmental copper ions (Cu²⁺) was developed according to the vibrational spectral change of diethyldithiocarbamate (DDTC) on gold nanoparticles (AuNPs). The ultraviolet-visible (UV-Vis) absorption spectra indicated that DDTC formed a complex with Cu²⁺ [...] Read more.

A surface-enhanced Raman scattering (SERS) detection method for environmental copper ions (Cu²⁺) was developed according to the vibrational spectral change of diethyldithiocarbamate (DDTC) on gold nanoparticles (AuNPs). The ultraviolet-visible (UV-Vis) absorption spectra indicated that DDTC formed a complex with Cu²⁺, showing a prominent peak at ~450 nm. We found Raman spectral changes in DDTC from ~1490 cm⁻¹ to ~1504 cm⁻¹ on AuNPs at a high concentration of Cu²⁺ above 1 μM. The other ions of Zn²⁺, Pb²⁺, Ni²⁺, NH₄⁺, Mn²⁺, Mg²⁺, K⁺, Hg²⁺, Fe²⁺, Fe³⁺, Cr³⁺, Co²⁺, Cd²⁺, and Ca²⁺ did not produce such spectral changes, even after they reacted with DDTC. The electroplating industrial wastewater samples were tested under the interference of highly concentrated ions of Fe³⁺, Ni²⁺, and Zn²⁺. The Raman spectroscopy-based quantification of Cu²⁺ ions was able to be achieved for the wastewater after treatment with alkaline chlorination, whereas the cyanide-containing water did not show any spectral changes, due to the complexation of the cyanide with the Cu²⁺ ions. A micromolar range detection limit of Cu²⁺ ions could be achieved by analyzing the Raman spectra of DDTC in the cyanide-removed water. Full article

(This article belongs to the Special Issue Surface Plasmon Resonance Sensing)

► Show Figures

Figure 1

3658 KiB

Open AccessArticle

Mach-Zehnder Interferometer Refractive Index Sensor Based on a Plasmonic Channel Waveguide

by Da Eun Lee, Young Jin Lee, Eunso Shin and Soon-Hong Kwon

Sensors 2017, 17(11), 2584; https://doi.org/10.3390/s17112584 - 9 Nov 2017

Cited by 17 | Viewed by 5137

Abstract

A Mach-Zehnder interferometer based on a plasmonic channel waveguide is proposed for refractive index sensing. The structure, with a small physical footprint of 20 × 120 μm², achieved a high figure of merit of 294. The cut-off frequency behaviour in the [...] Read more.

A Mach-Zehnder interferometer based on a plasmonic channel waveguide is proposed for refractive index sensing. The structure, with a small physical footprint of 20 × 120 μm², achieved a high figure of merit of 294. The cut-off frequency behaviour in the plasmonic channel waveguide resulted in a flat dispersion curve, which induces a 1.8 times larger change of the propagation constant for the given refractive index change compared with previously reported results. Full article

(This article belongs to the Special Issue Surface Plasmon Resonance Sensing)

► Show Figures

Figure 1

3536 KiB

Open AccessArticle

Surface-Enhanced Resonance Raman Scattering of Rhodamine 6G in Dispersions and on Films of Confeito-Like Au Nanoparticles

by Masaki Ujihara, Nhut Minh Dang and Toyoko Imae

Sensors 2017, 17(11), 2563; https://doi.org/10.3390/s17112563 - 7 Nov 2017

Cited by 21 | Viewed by 6363

Abstract

Surface-enhanced resonance Raman scattering (SERRS) of rhodamine 6G was measured on confeito-like Au nanoparticles (CAuNPs). The large CAuNPs (100 nm in diameter) in aqueous dispersion systems showed stronger enhancing effect (analytical enhancement factor: over 10⁵) of SERRS than the small CAuNPs [...] Read more.

Surface-enhanced resonance Raman scattering (SERRS) of rhodamine 6G was measured on confeito-like Au nanoparticles (CAuNPs). The large CAuNPs (100 nm in diameter) in aqueous dispersion systems showed stronger enhancing effect (analytical enhancement factor: over 10⁵) of SERRS than the small CAuNPs (50 nm in diameter), while the spherical Au nanoparticles (20 nm in diameter) displayed rather weak intensities. Especially, minor bands in 1400–1600 cm⁻¹ were uniquely enhanced by the resonance effect of CAuNPs. The enhancement factors revealed a concentration dependence of the enhancing effect at low concentration of rhodamine 6G. This dependency was due to a large capacity of hot-spots on CAuNPs, which were formed without agglomeration. The surface-enhancing behaviour in the film systems was similar to that in the dispersions, although the large CAuNPs had lower enhancing effect in the films, and the small CAuNPs and the spherical Au nanoparticles were more effective in their films. These results suggest that the CAuNPs have an advantage in ultrasensitive devices both in dispersions and films, compared to the agglomerate of spherical Au nanoparticles. Full article

(This article belongs to the Special Issue Surface Plasmon Resonance Sensing)

► Show Figures

Graphical abstract

3415 KiB

Open AccessArticle

Plasmonic Waveguide Coupled Ring Cavity for a Non-Resonant Type Refractive Index Sensor

by Soon-Hong Kwon

Sensors 2017, 17(11), 2526; https://doi.org/10.3390/s17112526 - 3 Nov 2017

Cited by 8 | Viewed by 4950

Abstract

Sensitive refractive index sensors with small footprints have been studied to allow the integration of a large number of sensors into a tiny chip for bio/chemical applications. In particular, resonant-type index sensors based on various micro/nanocavities, which use a resonant wavelength dependence on [...] Read more.

Sensitive refractive index sensors with small footprints have been studied to allow the integration of a large number of sensors into a tiny chip for bio/chemical applications. In particular, resonant-type index sensors based on various micro/nanocavities, which use a resonant wavelength dependence on the refractive index of the analyte, have been developed. However, the spectral linewidth of the resonance, which becomes the resolution limit, is considerably large in plasmonic cavities due to the large absorption loss of metals. Therefore, there is demand for a new type of plasmonic refractive index sensor that is not limited by the linewidth of the cavity. We propose a new type of plasmonic index sensors consisting of a channel waveguide and a ring cavity. Two emissions from the ring cavity in both directions of the waveguide couple with a reflection phase difference depending on the length of a closed right arm with a reflecting boundary. Therefore, the output power dramatically and sensitively changes as a function of the refractive index of the analyte filling the waveguide. Full article

(This article belongs to the Special Issue Surface Plasmon Resonance Sensing)

► Show Figures

Graphical abstract

3263 KiB

Open AccessArticle

Surface Acoustic Wave (SAW)-Enhanced Chemical Functionalization of Gold Films

by Gina Greco, Matteo Agostini, Richie Shilton, Marco Travagliati, Giovanni Signore and Marco Cecchini

Sensors 2017, 17(11), 2452; https://doi.org/10.3390/s17112452 - 26 Oct 2017

Cited by 12 | Viewed by 6118

Abstract

Surface chemical and biochemical functionalization is a fundamental process that is widely applied in many fields to add new functions, features, or capabilities to a material’s surface. Here, we demonstrate that surface acoustic waves (SAWs) can enhance the chemical functionalization of gold films. [...] Read more.

Surface chemical and biochemical functionalization is a fundamental process that is widely applied in many fields to add new functions, features, or capabilities to a material’s surface. Here, we demonstrate that surface acoustic waves (SAWs) can enhance the chemical functionalization of gold films. This is shown by using an integrated biochip composed by a microfluidic channel coupled to a surface plasmon resonance (SPR) readout system and by monitoring the adhesion of biotin-thiol on the gold SPR areas in different conditions. In the case of SAW-induced streaming, the functionalization efficiency is improved

\approx 5

times with respect to the case without SAWs. The technology here proposed can be easily applied to a wide variety of biological systems (e.g., proteins, nucleic acids) and devices (e.g., sensors, devices for cell cultures). Full article

(This article belongs to the Special Issue Surface Plasmon Resonance Sensing)

► Show Figures

Figure 1

3996 KiB

Open AccessArticle

Lab-on-Chip, Surface-Enhanced Raman Analysis by Aerosol Jet Printing and Roll-to-Roll Hot Embossing

by Anne Habermehl, Noah Strobel, Ralph Eckstein, Nico Bolse, Adrian Mertens, Gerardo Hernandez-Sosa, Carsten Eschenbaum and Uli Lemmer

Sensors 2017, 17(10), 2401; https://doi.org/10.3390/s17102401 - 20 Oct 2017

Cited by 19 | Viewed by 7273

Abstract

Surface-enhanced Raman spectroscopy (SERS) combines the high speciﬁcity of Raman scattering with high sensitivity due to an enhancement of the electromagnetic ﬁeld by metallic nanostructures. However, the tyical fabrication methods of SERS substrates suffer from low throughput and therefore high costs. Furthermore, point-of-care [...] Read more.

Surface-enhanced Raman spectroscopy (SERS) combines the high speciﬁcity of Raman scattering with high sensitivity due to an enhancement of the electromagnetic ﬁeld by metallic nanostructures. However, the tyical fabrication methods of SERS substrates suffer from low throughput and therefore high costs. Furthermore, point-of-care applications require the investigation of liquid solutions and thus the integration of the SERS substrate in a microfluidic chip. We present a roll-to-roll fabrication approach for microfluidics with integrated, highly efficient, surface-enhanced Raman scattering structures. Microfluidic channels are formed using roll-to-roll hot embossing in polystyrene foil. Aerosol jet printing of a gold nanoparticle ink is utilized to manufacture highly efficient, homogeneous, and reproducible SERS structures. The modified channels are sealed with a solvent-free, roll-to-roll, thermal bonding process. In continuous flow measurements, these chips overcome time-consuming incubation protocols and the poor reproducibility of SERS experiments often caused by inhomogeneous drying of the analyte. In the present study, we explore the influence of the printing process on the homogeneity and the enhancement of the SERS structures. The feasibility of aerosol-jet-modified microfluidic channels for highly sensitive SERS detection is demonstrated by using solutions with different concentrations of Rhodamine 6G and adenosine. The printed areas provide homogeneous enhancement factors of ~4 × 10⁶. Our work shows a way towards the low-cost production of tailor-made, SERS-enabled, label-free, lab-on- chip systems for bioanalysis. Full article

(This article belongs to the Special Issue Surface Plasmon Resonance Sensing)

► Show Figures

Figure 1

1615 KiB

Open AccessArticle

A Phase-Intensity Surface Plasmon Resonance Biosensor for Avian Influenza A (H5N1) Detection

by Chi Lok Wong, Marissa Chua, Heather Mittman, Li Xian Choo, Hann Qian Lim and Malini Olivo

Sensors 2017, 17(10), 2363; https://doi.org/10.3390/s17102363 - 16 Oct 2017

Cited by 37 | Viewed by 6161

Abstract

In this paper, we present a phase-intensity surface plasmon resonance (SPR) biosensor and demonstrate its use for avian influenza A (H5N1) antibody biomarker detection. The sensor probes the intensity variation produced by the steep phase response at surface plasmon excitation. The prism sensor [...] Read more.

In this paper, we present a phase-intensity surface plasmon resonance (SPR) biosensor and demonstrate its use for avian influenza A (H5N1) antibody biomarker detection. The sensor probes the intensity variation produced by the steep phase response at surface plasmon excitation. The prism sensor head is fixed between a pair of polarizers with a perpendicular orientation angle and a forbidden transmission path. At SPR, a steep phase change is introduced between the p- and s-polarized light, and this rotates the polarization ellipse of the transmission beam. This allows the light at resonance to be transmitted and a corresponding intensity change to be detected. Neither time-consuming interference fringe analysis nor a phase extraction process is required. In refractive index sensing experiments, the sensor resolution was determined to be 6.3 × 10⁻⁶ refractive index values (RIU). The sensor has been further applied for H5N1 antibody biomarker detection, and the sensor resolution was determined to be 193.3 ng mL⁻¹, compared to 1 μg mL⁻¹ and 0.5 μg mL⁻¹, as reported in literature for influenza antibody detection using commercial Biacore systems. It represents a 517.3% and 258.7% improvement in detection limit, respectively. With the unique features of label-free, real-time, and sensitive detection, the phase-intensity SPR biosensor has promising potential applications in influenza detection. Full article

(This article belongs to the Special Issue Surface Plasmon Resonance Sensing)

► Show Figures

Figure 1

3071 KiB

Open AccessArticle

A Novel Fiber Optic Surface Plasmon Resonance Biosensors with Special Boronic Acid Derivative to Detect Glycoprotein

by Yang Zhang, Fang Wang, Siyu Qian, Zexu Liu, Qiao Wang, Yiying Gu, Zhenlin Wu, Zhenguo Jing, Changsen Sun and Wei Peng

Sensors 2017, 17(10), 2259; https://doi.org/10.3390/s17102259 - 1 Oct 2017

Cited by 42 | Viewed by 6832

Abstract

We proposed and demonstrated a novel tilted fiber Bragg grating (TFBG)-based surface plasmon resonance (SPR) label-free biosensor via a special boronic acid derivative to detect glycoprotein with high sensitivity and selectivity. TFBG, as an effective sensing element for optical sensing in near-infrared wavelengths, [...] Read more.

We proposed and demonstrated a novel tilted fiber Bragg grating (TFBG)-based surface plasmon resonance (SPR) label-free biosensor via a special boronic acid derivative to detect glycoprotein with high sensitivity and selectivity. TFBG, as an effective sensing element for optical sensing in near-infrared wavelengths, possess the unique capability of easily exciting the SPR effect on fiber surface which coated with a nano-scale metal layer. SPR properties can be accurately detected by measuring the variation of transmitted spectra at optical communication wavelengths. In our experiment, a 10° TFBG coated with a 50 nm gold film was manufactured to stimulate SPR on a sensor surface. To detect glycoprotein selectively, the sensor was immobilized using designed phenylboronic acid as the recognition molecule, which can covalently bond with 1,2- or 1,3-diols to form five- or six-membered cyclic complexes for attaching diol-containing biomolecules and proteins. The phenylboronic acid was synthetized with long alkyl groups offering more flexible space, which was able to improve the capability of binding glycoprotein. The proposed TFBG-SPR sensors exhibit good selectivity and repeatability with a protein concentration sensitivity up to 2.867 dB/ (mg/mL) and a limit of detection (LOD) of 15.56 nM. Full article

(This article belongs to the Special Issue Surface Plasmon Resonance Sensing)

► Show Figures

Figure 1

1987 KiB

Open AccessArticle

Development and Validation of a Reproducible and Label-Free Surface Plasmon Resonance Immunosensor for Enrofloxacin Detection in Animal-Derived Foods

by Mingfei Pan, Shijie Li, Junping Wang, Wei Sheng and Shuo Wang

Sensors 2017, 17(9), 1984; https://doi.org/10.3390/s17091984 - 30 Aug 2017

Cited by 30 | Viewed by 5519

Abstract

This study describes the development of a reproducible and label-free surface plasmon resonance (SPR) immunosensor and its application in the detection of harmful enrofloxacin (ENRO) in animal-derived foods. The experimental parameters for the immunosensor construction and regeneration, including the pH value (4.5), concentration [...] Read more.

This study describes the development of a reproducible and label-free surface plasmon resonance (SPR) immunosensor and its application in the detection of harmful enrofloxacin (ENRO) in animal-derived foods. The experimental parameters for the immunosensor construction and regeneration, including the pH value (4.5), concentration for coating ENRO-ovalbumin conjugate (ENRO-OVA) (100 μg·mL⁻¹), concentration of anti-ENRO antibody (80 nM) and regeneration solution (0.1 mol·L⁻¹ HCl) were evaluated in detail. With the optimized parameters, the proposed SPR immunosensor obtained a good linear response to ENRO with high sensitivity (IC₅₀: 3.8 ng·mL⁻¹) and low detection limit (IC₁₅: 1.2 ng·mL⁻¹). The proposed SPR immunosensor was further validated to have favorable performances for ENRO residue detection in typical animal-derived foods after a simple matrix pretreatment procedure, as well as acceptable accuracy (recovery: 84.3–96.6%), precision (relative standard deviation (n = 3): 1.8–4.6%), and sensitivity (IC₁₅ ≤ 8.4 ng·mL⁻¹). Each SPR chip for analysis can be reused at least 100 times with good stability and the analysis cycle containing the steps of sample uploading/chip regeneration/baseline recovery can be completed within 6 min (one cycle) and auto-operated by a predetermined program. These results demonstrated that the proposed SPR immunosensor provided an effective strategy for accurate, sensitive, and rapid detection for ENRO residue, which has great potential for routine analysis of large numbers of samples for measuring different types of compounds. Full article

(This article belongs to the Special Issue Surface Plasmon Resonance Sensing)

► Show Figures

Figure 1

2833 KiB

Open AccessArticle

Ultrasensitive Terahertz Biosensors Based on Fano Resonance of a Graphene/Waveguide Hybrid Structure

by Banxian Ruan, Jun Guo, Leiming Wu, Jiaqi Zhu, Qi You, Xiaoyu Dai and Yuanjiang Xiang

Sensors 2017, 17(8), 1924; https://doi.org/10.3390/s17081924 - 21 Aug 2017

Cited by 55 | Viewed by 7031

Abstract

Graphene terahertz (THz) surface plasmons provide hope for developing functional devices in the THz frequency. By coupling graphene surface plasmon polaritons (SPPs) and a planar waveguide (PWG) mode, Fano resonances are demonstrated to realize an ultrasensitive terahertz biosensor. By analyzing the dispersion relation [...] Read more.

Graphene terahertz (THz) surface plasmons provide hope for developing functional devices in the THz frequency. By coupling graphene surface plasmon polaritons (SPPs) and a planar waveguide (PWG) mode, Fano resonances are demonstrated to realize an ultrasensitive terahertz biosensor. By analyzing the dispersion relation of graphene SPPs and PWG, the tunable Fano resonances in the terahertz frequency are discussed. It is found that the asymmetric lineshape of Fano resonances can be manipulated by changing the Fermi level of graphene, and the influence of the thickness of coupling layer and air layer in sandwich structure on the Fano resonances is also discussed in detail. We then apply the proposed Fano resonance to realize the ultrasensitive terahertz biosensors, it is shown that the highest sensitivities of 3260 RIU−1 are realized. Our result is two orders of a conventional surface plasmon resonance sensor. Furthermore, we find that when sensing medium is in the vicinity of water in THz, the sensitivity increases with increasing refractive index of the sensing medium. Full article

(This article belongs to the Special Issue Surface Plasmon Resonance Sensing)

► Show Figures

Figure 1

3889 KiB

Open AccessArticle

Waveguide Plasmon Resonance of Arrayed Metallic Nanostructures Patterned on a Soft Substrate by Direct Contact Printing Lithography

by Wei-Xiang Su, Chun-Ying Wu and Yung-Chun Lee

Sensors 2017, 17(8), 1867; https://doi.org/10.3390/s17081867 - 13 Aug 2017

Cited by 2 | Viewed by 5897

Abstract

This paper presents a direct contact printing method to obtain arrayed metallic nanostructures on a soft polymer substrate. It utilizes a polydimethylsiloxane (PDMS) mold replicated from silicon molds to transfer metallic nanopatterns onto a polymer substrate based on differences in interfacial bonding energy. [...] Read more.

This paper presents a direct contact printing method to obtain arrayed metallic nanostructures on a soft polymer substrate. It utilizes a polydimethylsiloxane (PDMS) mold replicated from silicon molds to transfer metallic nanopatterns onto a polymer substrate based on differences in interfacial bonding energy. Arrayed metallic nanodisks with a disk diameter down to 180 nm and a center-to-center pitch around 400 nm are experimentally patterned on a PET substrate. The patterned metallic nanostructures are then spin-coated with a polymer layer; which mechanically secures the patterned nanostructures and optically allows waveguide plasmon resonance being excited by incident EM waves. Both experimental works and theoretical modeling are given to illustrate the behaviors of different types of plasmon resonance. These arrayed metallic nanostructures patterned on a soft polymer substrate and their tunable optical characteristics open up many possibilities in future engineering applications. Full article

(This article belongs to the Special Issue Surface Plasmon Resonance Sensing)

► Show Figures

Figure 1

1976 KiB

Open AccessArticle

Figure of Merit Enhancement of a Surface Plasmon Resonance Sensor Using a Low-Refractive-Index Porous Silica Film

by Qing-Qing Meng, Xin Zhao, Cheng-You Lin, Shu-Jing Chen, Ying-Chun Ding and Zhao-Yang Chen

Sensors 2017, 17(8), 1846; https://doi.org/10.3390/s17081846 - 10 Aug 2017

Cited by 79 | Viewed by 8839

Abstract

In this paper; the surface plasmon resonance (SPR) sensor with a porous silica film was studied. The effect of the thickness and porosity of the porous silica film on the performance of the sensor was analyzed. The results indicated that the figure of [...] Read more.

In this paper; the surface plasmon resonance (SPR) sensor with a porous silica film was studied. The effect of the thickness and porosity of the porous silica film on the performance of the sensor was analyzed. The results indicated that the figure of merit (FOM) of an SPR sensor can be enhanced by using a porous silica film with a low-refractive-index. Particularly; the FOM of an SPR sensor with 40 nm thick 90% porosity porous silica film; whose refractive index is 1.04 was improved by 311% when compared with that of a traditional SPR sensor. Furthermore; it was found that the decrease in the refractive index or the increase in the thickness of the low-refractive-index porous silica film can enlarge the FOM enhancement. It is believed that the proposed SPR sensor with a low-refractive-index porous silica film will be helpful for high-performance SPR sensors development. Full article

(This article belongs to the Special Issue Surface Plasmon Resonance Sensing)

► Show Figures

Figure 1

1272 KiB

Open AccessArticle

Identification and Quantification of Celery Allergens Using Fiber Optic Surface Plasmon Resonance PCR

by Devin Daems, Bernd Peeters, Filip Delport, Tony Remans, Jeroen Lammertyn and Dragana Spasic

Sensors 2017, 17(8), 1754; https://doi.org/10.3390/s17081754 - 31 Jul 2017

Cited by 22 | Viewed by 6220

Abstract

Abstract: Accurate identification and quantification of allergens is key in healthcare, biotechnology and food quality and safety. Celery (Apium graveolens) is one of the most important elicitors of food allergic reactions in Europe. Currently, the golden standards to identify, quantify [...] Read more.

Abstract: Accurate identification and quantification of allergens is key in healthcare, biotechnology and food quality and safety. Celery (Apium graveolens) is one of the most important elicitors of food allergic reactions in Europe. Currently, the golden standards to identify, quantify and discriminate celery in a biological sample are immunoassays and two-step molecular detection assays in which quantitative PCR (qPCR) is followed by a high-resolution melting analysis (HRM). In order to provide a DNA-based, rapid and simple detection method suitable for one-step quantification, a fiber optic PCR melting assay (FO-PCR-MA) was developed to determine different concentrations of celery DNA (1 pM–0.1 fM). The presented method is based on the hybridization and melting of DNA-coated gold nanoparticles to the FO sensor surface in the presence of the target gene (mannitol dehydrogenase, Mtd). The concept was not only able to reveal the presence of celery DNA, but also allowed for the cycle-to-cycle quantification of the target sequence through melting analysis. Furthermore, the developed bioassay was benchmarked against qPCR followed by HRM, showing excellent agreement (R² = 0.96). In conclusion, this innovative and sensitive diagnostic test could further improve food quality control and thus have a large impact on allergen induced healthcare problems. Full article

(This article belongs to the Special Issue Surface Plasmon Resonance Sensing)

► Show Figures

Figure 1

3506 KiB

Open AccessArticle

Rapid Surface Enhanced Raman Scattering (SERS) Detection of Sibutramine Hydrochloride in Pharmaceutical Capsules with a β-Cyclodextrin- Ag/Polyvivnyl Alcohol Hydrogel Substrate

by Lei Ouyang, Zuyan Jiang, Nan Wang, Lihua Zhu and Heqing Tang

Sensors 2017, 17(7), 1601; https://doi.org/10.3390/s17071601 - 10 Jul 2017

Cited by 17 | Viewed by 7620

Abstract

Sibutramine hydrochloride (SH) is a banned weight-loss drug, but its illegal addition to health products is still rampant. This suggests a very urgent need for a fast and precise detection method for SH. Surface Enhanced Raman Scattering (SERS) is a promising candidate for [...] Read more.

Sibutramine hydrochloride (SH) is a banned weight-loss drug, but its illegal addition to health products is still rampant. This suggests a very urgent need for a fast and precise detection method for SH. Surface Enhanced Raman Scattering (SERS) is a promising candidate for this purpose, but the weak affinity between SH and bare metal limits its direct SERS detection. In the present work, β-cyclodextrin was capped in situ onto the surface of Ag nanoparticles to function as a scaffold to capture SH. The obtained Ag nanoparticles were encapsulated into polyvinyl alcohol (PVA) to fabricate a SERS active hydrogel with excellent reproducibility. A facile SERS strategy based on such substrate was proposed for trace SH quantification with a linear range of 7.0–150.0 µg·mL^–1, and a detection limit low to 3.0 µg·mL⁻¹. It was applied to analyze seven types of commercial slimming capsules with satisfactory results, showing good prospect for real applications. Full article

(This article belongs to the Special Issue Surface Plasmon Resonance Sensing)

► Show Figures

Graphical abstract

2701 KiB

Open AccessArticle

Slab Waveguide and Optical Fibers for Novel Plasmonic Sensor Configurations

by Nunzio Cennamo, Francesco Mattiello and Luigi Zeni

Sensors 2017, 17(7), 1488; https://doi.org/10.3390/s17071488 - 24 Jun 2017

Cited by 28 | Viewed by 6188

Abstract

The use of plasmonic sensor devices often requires replaceable parts and disposable chips for easy, fast and on-site detection analysis. In light of these requests, we propose a novel low-cost surface plasmon resonance sensor platform for possible selective detection of analytes in aqueous [...] Read more.

The use of plasmonic sensor devices often requires replaceable parts and disposable chips for easy, fast and on-site detection analysis. In light of these requests, we propose a novel low-cost surface plasmon resonance sensor platform for possible selective detection of analytes in aqueous solutions. It is based on a Polymethyl methacrylate (PMMA) slab waveguide with a thin gold film on the top surface inserted in a special holder, designed to produce the plasmonic resonance at the gold-dielectric interface. A wide-band light is launched in the PMMA slab waveguide through a trench realized in the holder directly, and illuminated with a PMMA plastic optical fiber (POF) to excite surface Plasmon waves. The output light is then collected by another PMMA POF kept at the end of the slab at an angle of 90° to the trench, and carried to a spectrometer. In this configuration, the trench has been used because a large incident angle is required for surface plasmon resonance excitation. The preliminary results showed that the sensor’s performances make it suitable for bio-chemical applications. The easy replacement of the chip allows for the production of an engineered platform by simplifying the measurement procedures. Full article

(This article belongs to the Special Issue Surface Plasmon Resonance Sensing)

► Show Figures

Figure 1

1792 KiB

Open AccessArticle

Design and Performance of a Portable and Multichannel SPR Device

by Xiao-ling Zhang, Yan Liu, Ting Fan, Ning Hu, Zhong Yang, Xi Chen, Zhen-yu Wang and Jun Yang

Sensors 2017, 17(6), 1435; https://doi.org/10.3390/s17061435 - 19 Jun 2017

Cited by 17 | Viewed by 8408

Abstract

A portable multichannel surface plasmon resonance (SPR) biosensor device is presented in this study. As an optical biosensor device, the core component of its light path is a semi-cylindrical prism, which is used as the coupling unit for the excitation of the SPR [...] Read more.

A portable multichannel surface plasmon resonance (SPR) biosensor device is presented in this study. As an optical biosensor device, the core component of its light path is a semi-cylindrical prism, which is used as the coupling unit for the excitation of the SPR phenomena. Based on this prism, a wedge-shaped incident light beam including a continuous angle range (10°) is chosen to replace the commonly-used parallel light beam in traditional SPR devices, in which the incident angle is adjusted by a sophisticated mechanical system. Thus, complicated, cumbersome, and costly mechanical structures can be avoided in this design. Furthermore, the selection of a small and high-stability semiconductor laser and matrix CCD detector as well as a microfluidic system aids in the realization of a miniaturized and multichannel device. Several different samples were used to test the performance of this new device. For ethanol with different concentrations, the sensing response was of good linear relativity with the concentration (Y = 3.17143X + 2.81518, R² = 0.97661). Mouse IgG and goat anti-mouse IgG were used as biological samples for immunological analysis, and BSA as the control group. Good specific recognition between mouse IgG and goat anti-mouse IgG has been achieved. The detection limit of antibody to antigen coated on the sensing surface was about 25 mg/L without surface modification. Full article

(This article belongs to the Special Issue Surface Plasmon Resonance Sensing)

► Show Figures

Figure 1

1990 KiB

Open AccessArticle

Nanoporous Gold Films Prepared by a Combination of Sputtering and Dealloying for Trace Detection of Benzo[a]pyrene Based on Surface Plasmon Resonance Spectroscopy

by Li Wang, Xiu-Mei Wan, Ran Gao, Dan-Feng Lu and Zhi-Mei Qi

Sensors 2017, 17(6), 1255; https://doi.org/10.3390/s17061255 - 1 Jun 2017

Cited by 15 | Viewed by 5850

Abstract

A wavelength-interrogated surface plasmon resonance (SPR) sensor based on a nanoporous gold (NPG) film has been fabricated for the sensitive detection of trace quantities of benzo[a]pyrene (BaP) in water. The large-area uniform NPG film was prepared by a two-step process that includes sputtering [...] Read more.

A wavelength-interrogated surface plasmon resonance (SPR) sensor based on a nanoporous gold (NPG) film has been fabricated for the sensitive detection of trace quantities of benzo[a]pyrene (BaP) in water. The large-area uniform NPG film was prepared by a two-step process that includes sputtering deposition of a 60-nm-thick AuAg alloy film on a glass substrate and chemical dealloying of the alloy film in nitric acid. For SPR sensor applications, the NPG film plays the dual roles of analyte enrichment and supporting surface plasmon waves, which leads to sensitivity enhancement. In this work, the as-prepared NPG film was first modified with 1-dodecanethiol molecules to make the film hydrophobic so as to improve BaP enrichment from water via hydrophobic interactions. The SPR sensor with the hydrophobic NPG film enables one to detect BaP at concentrations as low as 1 nmol·L⁻¹. In response to this concentration of BaP the sensor produced a resonance-wavelength shift of Δλ_R = 2.22 nm. After the NPG film was functionalized with mouse monoclonal IgG1 that is the antibody against BaP, the sensor’s sensitivity was further improved and the BaP detection limit decreased further down to 5 pmol·L⁻¹ (the corresponding Δλ_R = 1.77 nm). In contrast, the conventional SPR sensor with an antibody-functionalized dense gold film can give a response of merely Δλ_R = 0.9 nm for 100 pmol·L⁻¹ BaP. Full article

(This article belongs to the Special Issue Surface Plasmon Resonance Sensing)

► Show Figures

Figure 1

Review

Jump to: Research

2929 KiB

Open AccessReview

A Localized Surface Plasmon Resonance Sensor Using Double-Metal-Complex Nanostructures and a Review of Recent Approaches

by Heesang Ahn, Hyerin Song, Jong-ryul Choi and Kyujung Kim

Sensors 2018, 18(1), 98; https://doi.org/10.3390/s18010098 - 31 Dec 2017

Cited by 40 | Viewed by 10546

Abstract

From active developments and applications of various devices to acquire outside and inside information and to operate based on feedback from that information, the sensor market is growing rapidly. In accordance to this trend, the surface plasmon resonance (SPR) sensor, an optical sensor, [...] Read more.

From active developments and applications of various devices to acquire outside and inside information and to operate based on feedback from that information, the sensor market is growing rapidly. In accordance to this trend, the surface plasmon resonance (SPR) sensor, an optical sensor, has been actively developed for high-sensitivity real-time detection. In this study, the fundamentals of SPR sensors and recent approaches for enhancing sensing performance are reported. In the section on the fundamentals of SPR sensors, a brief description of surface plasmon phenomena, SPR, SPR-based sensing applications, and several configuration types of SPR sensors are introduced. In addition, advanced nanotechnology- and nanofabrication-based techniques for improving the sensing performance of SPR sensors are proposed: (1) localized SPR (LSPR) using nanostructures or nanoparticles; (2) long-range SPR (LRSPR); and (3) double-metal-layer SPR sensors for additional performance improvements. Consequently, a high-sensitivity, high-biocompatibility SPR sensor method is suggested. Moreover, we briefly describe issues (miniaturization and communication technology integration) for future SPR sensors. Full article

(This article belongs to the Special Issue Surface Plasmon Resonance Sensing)

► Show Figures

Figure 1

1425 KiB

Open AccessReview

Phase-Sensitive Surface Plasmon Resonance Sensors: Recent Progress and Future Prospects

by Shijie Deng, Peng Wang and Xinglong Yu

Sensors 2017, 17(12), 2819; https://doi.org/10.3390/s17122819 - 5 Dec 2017

Cited by 74 | Viewed by 7988

Abstract

Surface plasmon resonance (SPR) is an optical sensing technique that is capable of performing real-time, label-free and high-sensitivity monitoring of molecular interactions. SPR biosensors can be divided according to their operating principles into angle-, wavelength-, intensity- and phase-interrogated devices. With their complex optical [...] Read more.

Surface plasmon resonance (SPR) is an optical sensing technique that is capable of performing real-time, label-free and high-sensitivity monitoring of molecular interactions. SPR biosensors can be divided according to their operating principles into angle-, wavelength-, intensity- and phase-interrogated devices. With their complex optical configurations, phase-interrogated SPR sensors generally provide higher sensitivity and throughput, and have thus recently emerged as prominent biosensing devices. To date, several methods have been developed for SPR phase interrogation, including heterodyne detection, polarimetry, shear interferometry, spatial phase modulation interferometry and temporal phase modulation interferometry. This paper summarizes the fundamentals of phase-sensitive SPR sensing, reviews the available methods for phase interrogation of these sensors, and discusses the future prospects for and trends in the development of this technology. Full article

(This article belongs to the Special Issue Surface Plasmon Resonance Sensing)

► Show Figures

Figure 1

4849 KiB

Open AccessReview

Plasmonic Optical Fiber-Grating Immunosensing: A Review

by Tuan Guo, Álvaro González-Vila, Médéric Loyez and Christophe Caucheteur

Sensors 2017, 17(12), 2732; https://doi.org/10.3390/s17122732 - 26 Nov 2017

Cited by 107 | Viewed by 10463

Abstract

Plasmonic immunosensors are usually made of a noble metal (in the form of a film or nanoparticles) on which bioreceptors are grafted to sense analytes based on the antibody/antigen or other affinity mechanism. Optical fiber configurations are a miniaturized counterpart to the bulky [...] Read more.

Plasmonic immunosensors are usually made of a noble metal (in the form of a film or nanoparticles) on which bioreceptors are grafted to sense analytes based on the antibody/antigen or other affinity mechanism. Optical fiber configurations are a miniaturized counterpart to the bulky Kretschmann prism and allow easy light injection and remote operation. To excite a surface plasmon (SP), the core-guided light is locally outcoupled. Unclad optical fibers were the first configurations reported to this end. Among the different architectures able to bring light in contact with the surrounding medium, a great quantity of research is today being conducted on metal-coated fiber gratings photo-imprinted in the fiber core, as they provide modal features that enable SP generation at any wavelength, especially in the telecommunication window. They are perfectly suited for use with cost-effective high-resolution interrogators, allowing both a high sensitivity and a low limit of detection to be reached in immunosensing. This paper will review recent progress made in this field with different kinds of gratings: uniform, tilted and eccentric short-period gratings as well as long-period fiber gratings. Practical cases will be reported, showing that such sensors can be used in very small volumes of analytes and even possibly applied to in vivo diagnosis. Full article

(This article belongs to the Special Issue Surface Plasmon Resonance Sensing)

► Show Figures

Figure 1

5962 KiB

Open AccessReview

Surface Plasmon Resonance Sensors on Raman and Fluorescence Spectroscopy

by Jiangcai Wang, Weihua Lin, En Cao, Xuefeng Xu, Wenjie Liang and Xiaofang Zhang

Sensors 2017, 17(12), 2719; https://doi.org/10.3390/s17122719 - 24 Nov 2017

Cited by 70 | Viewed by 10377

Abstract

The performance of chemical reactions has been enhanced immensely with surface plasmon resonance (SPR)-based sensors. In this review, the principle and application of SPR sensors are introduced and summarized thoroughly. We introduce the mechanism of the SPR sensors and present a thorough summary [...] Read more.

The performance of chemical reactions has been enhanced immensely with surface plasmon resonance (SPR)-based sensors. In this review, the principle and application of SPR sensors are introduced and summarized thoroughly. We introduce the mechanism of the SPR sensors and present a thorough summary about the optical design, including the substrate and excitation modes of the surface plasmons. Additionally, the applications based on SPR sensors are described by the Raman and fluorescence spectroscopy in plasmon-driven surface catalytic reactions and the measurement of refractive index sensing, especially. Full article

(This article belongs to the Special Issue Surface Plasmon Resonance Sensing)

► Show Figures

Figure 1

32795 KiB

Open AccessReview

Selectivity/Specificity Improvement Strategies in Surface-Enhanced Raman Spectroscopy Analysis

by Feng Wang, Shiyu Cao, Ruxia Yan, Zewei Wang, Dan Wang and Haifeng Yang

Sensors 2017, 17(11), 2689; https://doi.org/10.3390/s17112689 - 21 Nov 2017

Cited by 61 | Viewed by 9146

Abstract

Surface-enhanced Raman spectroscopy (SERS) is a powerful technique for the discrimination, identification, and potential quantification of certain compounds/organisms. However, its real application is challenging due to the multiple interference from the complicated detection matrix. Therefore, selective/specific detection is crucial for the real application [...] Read more.

Surface-enhanced Raman spectroscopy (SERS) is a powerful technique for the discrimination, identification, and potential quantification of certain compounds/organisms. However, its real application is challenging due to the multiple interference from the complicated detection matrix. Therefore, selective/specific detection is crucial for the real application of SERS technique. We summarize in this review five selective/specific detection techniques (chemical reaction, antibody, aptamer, molecularly imprinted polymers and microfluidics), which can be applied for the rapid and reliable selective/specific detection when coupled with SERS technique. Full article

(This article belongs to the Special Issue Surface Plasmon Resonance Sensing)

► Show Figures

Figure 1

3241 KiB

Open AccessReview

Surface Plasmon Resonance Sensing of Biorecognition Interactions within the Tumor Suppressor p53 Network

by Ilaria Moscetti, Salvatore Cannistraro and Anna Rita Bizzarri

Sensors 2017, 17(11), 2680; https://doi.org/10.3390/s17112680 - 20 Nov 2017

Cited by 21 | Viewed by 5645

Abstract

Surface Plasmon Resonance (SPR) is a powerful technique to study the kinetics of biomolecules undergoing biorecognition processes, particularly suited for protein-protein interactions of biomedical interest. The potentiality of SPR was exploited to sense the interactions occurring within the network of the tumor suppressor [...] Read more.

Surface Plasmon Resonance (SPR) is a powerful technique to study the kinetics of biomolecules undergoing biorecognition processes, particularly suited for protein-protein interactions of biomedical interest. The potentiality of SPR was exploited to sense the interactions occurring within the network of the tumor suppressor p53, which is crucial for maintaining genome integrity and whose function is inactivated, mainly by down regulation or by mutation, in the majority of human tumors. This study includes p53 down-regulators, p53 mutants and also the p53 family members, p63 and p73, which could vicariate p53 protective function. Furthermore, the application of SPR was extended to sense the interaction of p53 with anti-cancer drugs, which might restore p53 function. An extended review of previous published work and unpublished kinetic data is provided, dealing with the interaction between the p53 family members, or their mutants and two anticancer molecules, Azurin and its cell-penetrating peptide, p28. All the kinetic results are discussed in connection with those obtained by a complementary approach operating at the single molecule level, namely Atomic Force Spectroscopy and the related literature data. The overview of the SPR kinetic results may significantly contribute to a deeper understanding of the interactions within p53 network, also in the perspective of designing suitable anticancer drugs. Full article

(This article belongs to the Special Issue Surface Plasmon Resonance Sensing)

► Show Figures

Figure 1

4193 KiB

Open AccessReview

Surface-Enhanced Raman Scattering in Molecular Junctions

by Madoka Iwane, Shintaro Fujii and Manabu Kiguchi

Sensors 2017, 17(8), 1901; https://doi.org/10.3390/s17081901 - 18 Aug 2017

Cited by 11 | Viewed by 8279

Abstract

Surface-enhanced Raman scattering (SERS) is a surface-sensitive vibrational spectroscopy that allows Raman spectroscopy on a single molecular scale. Here, we present a review of SERS from molecular junctions, in which a single molecule or molecules are made to have contact from the top [...] Read more.

Surface-enhanced Raman scattering (SERS) is a surface-sensitive vibrational spectroscopy that allows Raman spectroscopy on a single molecular scale. Here, we present a review of SERS from molecular junctions, in which a single molecule or molecules are made to have contact from the top to the bottom of metal surfaces. The molecular junctions are nice platforms for SERS as well as transport measurement. Electronic characterization based on the transport measurements of molecular junctions has been extensively studied for the development of miniaturized electronic devices. Simultaneous SERS and transport measurement of the molecular junctions allow both structural (geometrical) and electronic information on the single molecule scale. The improvement of SERS measurement on molecular junctions open the door toward new nanoscience and nanotechnology in molecular electronics. Full article

(This article belongs to the Special Issue Surface Plasmon Resonance Sensing)

► Show Figures

Figure 1

7957 KiB

Open AccessReview

Ag Nanorods-Oxide Hybrid Array Substrates: Synthesis, Characterization, and Applications in Surface-Enhanced Raman Scattering

by Lingwei Ma, Jianghao Li, Sumeng Zou and Zhengjun Zhang

Sensors 2017, 17(8), 1895; https://doi.org/10.3390/s17081895 - 17 Aug 2017

Cited by 9 | Viewed by 5991

Abstract

Over the last few decades, benefitting from the sufficient sensitivity, high specificity, nondestructive, and rapid detection capability of the surface-enhanced Raman scattering (SERS) technique, numerous nanostructures have been elaborately designed and successfully synthesized as high-performance SERS substrates, which have been extensively exploited for [...] Read more.

Over the last few decades, benefitting from the sufficient sensitivity, high specificity, nondestructive, and rapid detection capability of the surface-enhanced Raman scattering (SERS) technique, numerous nanostructures have been elaborately designed and successfully synthesized as high-performance SERS substrates, which have been extensively exploited for the identification of chemical and biological analytes. Among these, Ag nanorods coated with thin metal oxide layers (AgNRs-oxide hybrid array substrates) featuring many outstanding advantages have been proposed as fascinating SERS substrates, and are of particular research interest. The present review provides a systematic overview towards the representative achievements of AgNRs-oxide hybrid array substrates for SERS applications from diverse perspectives, so as to promote the realization of real-world SERS sensors. First, various fabrication approaches of AgNRs-oxide nanostructures are introduced, which are followed by a discussion on the novel merits of AgNRs-oxide arrays, such as superior SERS sensitivity and reproducibility, high thermal stability, long-term activity in air, corrosion resistivity, and intense chemisorption of target molecules. Next, we present recent advances of AgNRs-oxide substrates in terms of practical applications. Intriguingly, the recyclability, qualitative and quantitative analyses, as well as vapor-phase molecule sensing have been achieved on these nanocomposites. We further discuss the major challenges and prospects of AgNRs-oxide substrates for future SERS developments, aiming to expand the versatility of SERS technique. Full article

(This article belongs to the Special Issue Surface Plasmon Resonance Sensing)

► Show Figures

Figure 1

1591 KiB

Open AccessReview

Fano Effect and Quantum Entanglement in Hybrid Semiconductor Quantum Dot-Metal Nanoparticle System

by Yong He and Ka-Di Zhu

Sensors 2017, 17(6), 1445; https://doi.org/10.3390/s17061445 - 20 Jun 2017

Cited by 13 | Viewed by 6506

Abstract

In this paper, we review the investigation for the light-matter interaction between surface plasmon field in metal nanoparticle (MNP) and the excitons in semiconductor quantum dots (SQDs) in hybrid SQD-MNP system under the full quantum description. The exciton-plasmon interaction gives rise to the [...] Read more.

In this paper, we review the investigation for the light-matter interaction between surface plasmon field in metal nanoparticle (MNP) and the excitons in semiconductor quantum dots (SQDs) in hybrid SQD-MNP system under the full quantum description. The exciton-plasmon interaction gives rise to the modified decay rate and the exciton energy shift which are related to the exciton energy by using a quantum transformation method. We illustrate the responses of the hybrid SQD-MNP system to external field, and reveal Fano effect shown in the absorption spectrum. We demonstrate quantum entanglement between two SQD mediated by surface plasmon field. In the absence of a laser field, concurrence of quantum entanglement will disappear after a few ns. If the laser field is present, the steady states appear, so that quantum entanglement produced will reach a steady-state entanglement. Because one of all optical pathways to induce Fano effect refers to the generation of quantum entangled states, It is shown that the concurrence of quantum entanglement can be obtained by observation for Fano effect. In a hybrid system including two MNP and a SQD, because the two Fano quantum interference processes share a segment of all optical pathways, there is correlation between the Fano effects of the two MNP. The investigations for the light-matter interaction in hybrid SQD-MNP system can pave the way for the development of the optical processing devices and quantum information based on the exciton-plasmon interaction. Full article

(This article belongs to the Special Issue Surface Plasmon Resonance Sensing)

► Show Figures

Figure 1

Journal Menu

Journal Browser

Surface Plasmon Resonance Sensing

Share This Special Issue

Special Issue Editor

Special Issue Information

Keywords

Benefits of Publishing in a Special Issue

Published Papers (33 papers)

Research

Review

Further Information

Guidelines

MDPI Initiatives

Follow MDPI