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Nanotechnological Advances in Biosensors

A special issue of Sensors (ISSN 1424-8220). This special issue belongs to the section "Biosensors".

Deadline for manuscript submissions: closed (1 September 2009) | Viewed by 271323

Special Issue Editor


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Guest Editor
Department of Microbiology and Immunology, McGill University, Montreal, QC H3A2B4, Canada
Interests: ion channel biosensors; quantum dots for biological labeling; robotic chemistry lab for martian life

Special Issue Information

Dear Colleagues,

Coupling of biomolecules or complex biological systems with electronic or optoelectronic devices is the general principle of various biosensors. The effective performance of biosensors requires transduction of the chemical signals generated by the biological components to electronic signals. New methods and new materials (functionalized nanoparticles, carbon nanotubes, etc.) developed due to the tremendous recent success in nanotechnology pave the way for the novel possibilities to couple biomaterials and electronic transducers. The great importance of cooperative efforts in bioelectronics and nanotechnology, resulting in the formulation of the novel scientific direction named “bionanotechnology” cannot be overestimated. The recently born scientific direction has already attracted major interests of researches. Dimensional similarity of biomolecules and nano-objects allow their functional coupling, thus providing effective chemical/electronic signal transduction in the hybrid systems. The bionano-hybrid systems keep great promise for the development of novel biosensors, biofuel cells and biocomputing elements. Therefore, cooperative efforts of chemists, physicists and engineers from both science/technology areas (bioelectronics and nanotechnology) are needed to bring these promises into reality. These efforts should be directed to the basic science and to the technological development solving practical issues. The present special issue will outline the state-of-the-art in the area of nanotechnological advances in biosensors.

Dr. Jay Nadeau
Guest Editor

Keywords

  • bionanotechnology
  • nanotechnology
  • biosensors
  • nanomaterials
  • nanostructure
  • NEMS
  • functionalized nanoparticles
  • carbon nanotubes
  • biofuel cells
  • biocomputing

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Published Papers (17 papers)

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Editorial

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28 KiB  
Editorial
Editorial: Nanotechnological Advances in Biosensors
by Jay Nadeau
Sensors 2009, 9(11), 8907-8910; https://doi.org/10.3390/s91108907 - 9 Nov 2009
Cited by 4 | Viewed by 12050
Abstract
A biosensor is a physicochemical or hybrid physical-chemical-biological device that detects a biological molecule, organism, or process. Because of the nature of their targets, biosensors need to be faster, smaller, more sensitive, and more specific than nearly all of their physicochemical counterparts or [...] Read more.
A biosensor is a physicochemical or hybrid physical-chemical-biological device that detects a biological molecule, organism, or process. Because of the nature of their targets, biosensors need to be faster, smaller, more sensitive, and more specific than nearly all of their physicochemical counterparts or the traditional methods that they are designed to replace. Speed is of the essence in medical diagnosis as it permits for rapid, accurate treatment and does not allow patients to be lost to follow-up. Small size and greater sensitivity mean less-invasive sampling and detection of molecules such as neurotransmitters or hormones at biologically-relevant levels. Greater specificity allows assays to be performed in complex fluids such as blood or urine without false negative or false positive results. [...] Full article
(This article belongs to the Special Issue Nanotechnological Advances in Biosensors)

Research

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1302 KiB  
Article
Detecting Proteins in Highly Autofluorescent Cells Using Quantum Dot Antibody Conjugates
by Karen M. Orcutt, Shanshan Ren and Kjell Gundersen
Sensors 2009, 9(9), 7540-7549; https://doi.org/10.3390/s90907540 - 23 Sep 2009
Cited by 12 | Viewed by 12200
Abstract
We have applied quantum dot (Qdot) antibody conjugates as a biomolecular probe for cellular proteins important in biogeochemical cycling in the sea. Conventional immunological methods have been hampered by the strong autofluorescence found in cyanobacteria cells. Qdot conjugates provide an ideal alternative for [...] Read more.
We have applied quantum dot (Qdot) antibody conjugates as a biomolecular probe for cellular proteins important in biogeochemical cycling in the sea. Conventional immunological methods have been hampered by the strong autofluorescence found in cyanobacteria cells. Qdot conjugates provide an ideal alternative for studies that require long-term imaging of cells such as detection of low abundance cellular antigens by fluorescence microscopy. The advantage of Qdot labeled probes over conventional immunological methods is the photostability of the probe. Phycoerythrin bleaches in cyanobacterial cells under prolonged UV or blue light excitation, which means that the semiconducting nanocrystal probe, the Qdot, can yield a strong fluorescent signal without interference from cellular pigments. Full article
(This article belongs to the Special Issue Nanotechnological Advances in Biosensors)
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1513 KiB  
Article
A Novel Design of Grooved Fibers for Fiber-Optic Localized Plasmon Resonance Biosensors
by Ching-Te Huang, Chun-Ping Jen, Tzu-Chien Chao, Wei-Te Wu, Wan-Yun Li and Lai-Kwan Chau
Sensors 2009, 9(8), 6456-6470; https://doi.org/10.3390/s90806456 - 20 Aug 2009
Cited by 22 | Viewed by 12909
Abstract
Bio-molecular recognition is detected by the unique optical properties of self-assembled gold nanoparticles on the unclad portions of an optical fiber whose surfaces have been modified with a receptor. To enhance the performance of the sensing platform, the sensing element is integrated with [...] Read more.
Bio-molecular recognition is detected by the unique optical properties of self-assembled gold nanoparticles on the unclad portions of an optical fiber whose surfaces have been modified with a receptor. To enhance the performance of the sensing platform, the sensing element is integrated with a microfluidic chip to reduce sample and reagent volume, to shorten response time and analysis time, as well as to increase sensitivity. The main purpose of the present study is to design grooves on the optical fiber for the FO-LPR microfluidic chip and investigate the effect of the groove geometry on the biochemical binding kinetics through simulations. The optical fiber is designed and termed as U-type or D-type based on the shape of the grooves. The numerical results indicate that the design of the D-type fiber exhibits efficient performance on biochemical binding. The grooves designed on the optical fiber also induce chaotic advection to enhance the mixing in the microchannel. The mixing patterns indicate that D-type grooves enhance the mixing more effectively than U-type grooves. D-type fiber with six grooves is the optimum design according to the numerical results. The experimental results show that the D-type fiber could sustain larger elongation than the U-type fiber. Furthermore, this study successfully demonstrates the feasibility of fabricating the grooved optical fibers by the femtosecond laser, and making a transmission-based FO-LPR probe for chemical sensing. The sensor resolution of the sensor implementing the D-type fiber modified by gold nanoparticles was 4.1 × 10-7 RIU, which is much more sensitive than that of U-type optical fiber (1.8 × 10-3 RIU). Full article
(This article belongs to the Special Issue Nanotechnological Advances in Biosensors)
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680 KiB  
Article
From Lateral Flow Devices to a Novel Nano-Color Microfluidic Assay
by Saied Assadollahi, Christiane Reininger, Roland Palkovits, Peter Pointl and Thomas Schalkhammer
Sensors 2009, 9(8), 6084-6100; https://doi.org/10.3390/s90806084 - 31 Jul 2009
Cited by 21 | Viewed by 17652
Abstract
Improving the performance of traditional diagnostic lateral flow assays combined with new manufacturing technologies is a primary goal in the research and development plans of diagnostic companies. Taking into consideration the components of lateral flow diagnostic test kits; innovation can include modification of [...] Read more.
Improving the performance of traditional diagnostic lateral flow assays combined with new manufacturing technologies is a primary goal in the research and development plans of diagnostic companies. Taking into consideration the components of lateral flow diagnostic test kits; innovation can include modification of labels, materials and device design. In recent years, Resonance-Enhanced Absorption (REA) of metal nano-particles has shown excellent applicability in bio-sensing for the detection of a variety of bio-molecular binding interactions. In a novel approach, we have now integrated REA-assays in a diagnostic microfluidic setup thus resolving the bottleneck of long incubation times inherent in previously existing REA-assays and simultaneously integrated automated fabrication techniques for diagnostics manufacture. Due to the roller-coating based technology and chemical resistance, we used PET-co-polyester as a substrate and a CO2 laser ablation system as a fast, highly precise and contactless alternative to classical micro-milling. It was possible to detect biological binding within three minutes – visible to the eye as colored text readout within the REA-fluidic device. A two-minute in-situ silver enhancement was able to enhance the resonant color additionally, if required. Full article
(This article belongs to the Special Issue Nanotechnological Advances in Biosensors)
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733 KiB  
Article
A Portable and Autonomous Magnetic Detection Platform for Biosensing
by José Germano, Verónica C. Martins, Filipe A. Cardoso, Teresa M. Almeida, Leonel Sousa, Paulo P. Freitas and Moisés S. Piedade
Sensors 2009, 9(6), 4119-4137; https://doi.org/10.3390/s90604119 - 27 May 2009
Cited by 82 | Viewed by 14219
Abstract
This paper presents a prototype of a platform for biomolecular recognition detection. The system is based on a magnetoresistive biochip that performs biorecognition assays by detecting magnetically tagged targets. All the electronic circuitry for addressing, driving and reading out signals from spin-valve or [...] Read more.
This paper presents a prototype of a platform for biomolecular recognition detection. The system is based on a magnetoresistive biochip that performs biorecognition assays by detecting magnetically tagged targets. All the electronic circuitry for addressing, driving and reading out signals from spin-valve or magnetic tunnel junctions sensors is implemented using off-the-shelf components. Taking advantage of digital signal processing techniques, the acquired signals are processed in real time and transmitted to a digital analyzer that enables the user to control and follow the experiment through a graphical user interface. The developed platform is portable and capable of operating autonomously for nearly eight hours. Experimental results show that the noise level of the described platform is one order of magnitude lower than the one presented by the previously used measurement set-up. Experimental results also show that this device is able to detect magnetic nanoparticles with a diameter of 250 nm at a concentration of about 40 fM. Finally, the biomolecular recognition detection capabilities of the platform are demonstrated by performing a hybridization assay using complementary and non-complementary probes and a magnetically tagged 20mer single stranded DNA target. Full article
(This article belongs to the Special Issue Nanotechnological Advances in Biosensors)
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593 KiB  
Article
Micro-Pattern Guided Adhesion of Osteoblasts on Diamond Surfaces
by Bohuslav Rezek, Lenka Michalíková, Egor Ukraintsev, Alexander Kromka and Marie Kalbacova
Sensors 2009, 9(5), 3549-3562; https://doi.org/10.3390/s90503549 - 13 May 2009
Cited by 68 | Viewed by 12705
Abstract
Microscopic chemical patterning of diamond surfaces by hydrogen and oxygen surface atoms is used for self-assembly of human osteoblastic cells into micro-arrays. The cell adhesion and assembly is further controlled by concentration of cells (2,500-10,000 cells/cm2)and fetal bovine serum (0-15%). The [...] Read more.
Microscopic chemical patterning of diamond surfaces by hydrogen and oxygen surface atoms is used for self-assembly of human osteoblastic cells into micro-arrays. The cell adhesion and assembly is further controlled by concentration of cells (2,500-10,000 cells/cm2)and fetal bovine serum (0-15%). The cells are characterized by fluorescence microscopy of actin fibers and nuclei. The serum protein adsorption is studied by atomic force microscopy (AFM). The cells are arranged selectively on O-terminated patterns into 30-200 μm wide arrays. Higher cell concentrations allow colonization of unfavorable H-terminated regions due to mutual cell communication. There is no cell selectivity without the proteins in the medium. Based on the AFM, the proteins are present on both H- and O-terminated surfaces. Pronounced differences in their thickness, surface roughness, morphology, and phase imagesindicate different conformation of the proteins and explain the cell selectivity. Full article
(This article belongs to the Special Issue Nanotechnological Advances in Biosensors)
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702 KiB  
Article
Detection of Biomolecular Binding Through Enhancement of Localized Surface Plasmon Resonance (LSPR) by Gold Nanoparticles
by Hyung Min Kim, Seung Min Jin, Seok Kee Lee, Min-Gon Kim and Yong-Beom Shin
Sensors 2009, 9(4), 2334-2344; https://doi.org/10.3390/s90402334 - 30 Mar 2009
Cited by 58 | Viewed by 16556
Abstract
To amplify the difference in localized surface plasmon resonance (LSPR) spectra of gold nano-islands due to intermolecular binding events, gold nanoparticles were used. LSPR-based optical biosensors consisting of gold nano-islands were readily made on glass substrates using evaporation and heat treatment. Streptavidin (STA) [...] Read more.
To amplify the difference in localized surface plasmon resonance (LSPR) spectra of gold nano-islands due to intermolecular binding events, gold nanoparticles were used. LSPR-based optical biosensors consisting of gold nano-islands were readily made on glass substrates using evaporation and heat treatment. Streptavidin (STA) and biotinylated bovine serum albumin (Bio-BSA) were chosen as the model receptor and the model analyte, respectively, to demonstrate the effectiveness of this detection method. Using this model system, we were able to enhance the sensitivity in monitoring the binding of Bio-BSA to gold nano-island surfaces functionalized with STA through the addition of gold nanoparticle-STA conjugates. In addition, SU-8 well chips with gold nano-island surfaces were fabricated through a conventional UV patterning method and were then utilized for image detection using the attenuated total reflection mode. These results suggest that the gold nano-island well chip may have the potential to be used for multiple and simultaneous detection of various bio-substances. Full article
(This article belongs to the Special Issue Nanotechnological Advances in Biosensors)
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2663 KiB  
Communication
Development of an Electrogenerated Chemiluminescence Biosensor using Carboxylic acid-functionalized MWCNT and Au Nanoparticles
by Ming-Hua Piao, Dae-Soo Yang, Kuk-Ro Yoon, Seung-Ho Lee and Seong-Ho Choi
Sensors 2009, 9(3), 1662-1677; https://doi.org/10.3390/s90301662 - 9 Mar 2009
Cited by 22 | Viewed by 14620
Abstract
A COOH-F-MWCNT-Nafion-Ru(bpy)32+-Au-ADH electrogenerated chemi-luminescence (ECL)electrode using COOH-functionalized MWCNT (COOH-F-MWCNT) and Au nanoparticles synthesized by the radiation method was fabricated for ethanol sensing. A higher sensing efficiency for ethanol for the ECL biosensor prepared by PAAc-g-MWCNT was measured compared [...] Read more.
A COOH-F-MWCNT-Nafion-Ru(bpy)32+-Au-ADH electrogenerated chemi-luminescence (ECL)electrode using COOH-functionalized MWCNT (COOH-F-MWCNT) and Au nanoparticles synthesized by the radiation method was fabricated for ethanol sensing. A higher sensing efficiency for ethanol for the ECL biosensor prepared by PAAc-g-MWCNT was measured compared to that of the ECL biosensor prepared by PMAc-g-MWCNT, and purified MWCNT. Experimental parameters affecting ethanol detection were also examined in terms of pH and the content of PAAc-g-MWCNT in Nafion. Little interference of other compounds was observed for the assay of ethanol. Results suggest this ECL biosensor could be applied for ethanol detection in real samples. Full article
(This article belongs to the Special Issue Nanotechnological Advances in Biosensors)
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972 KiB  
Article
Efficient Chemical Sensing by Coupled Slot SOI Waveguides
by Vittorio M. N. Passaro, Francesco Dell’Olio, Caterina Ciminelli and Mario N. Armenise
Sensors 2009, 9(2), 1012-1032; https://doi.org/10.3390/s90201012 - 16 Feb 2009
Cited by 69 | Viewed by 13180
Abstract
A guided-wave chemical sensor for the detection of environmental pollutants or biochemical substances has been designed. The sensor is based on an asymmetric directional coupler employing slot optical waveguides. The use of a nanometer guiding structure where optical mode is confined in a [...] Read more.
A guided-wave chemical sensor for the detection of environmental pollutants or biochemical substances has been designed. The sensor is based on an asymmetric directional coupler employing slot optical waveguides. The use of a nanometer guiding structure where optical mode is confined in a low-index region permits a very compact sensor (device area about 1200 μm2) to be realized, having the minimum detectable refractive index change as low as 10-5. Silicon-on-Insulator technology has been assumed in sensor design and a very accurate modelling procedure based on Finite Element Method and Coupled Mode Theory has been pointed out. Sensor design and optimization have allowed a very good trade-off between device length and sensitivity. Expected device sensitivity to glucose concentration change in an aqueous solution is of the order of 0.1 g/L. Full article
(This article belongs to the Special Issue Nanotechnological Advances in Biosensors)
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292 KiB  
Article
Sensitivity Improvement of a Humidity Sensor Based on Silica Nanospheres on a Long-Period Fiber Grating
by Diana Viegas, Javier Goicoechea, José Luís Santos, Francisco Moita Araújo, Luís Alberto Ferreira, Francisco J. Arregui and Ignacio R. Matias
Sensors 2009, 9(1), 519-527; https://doi.org/10.3390/s90100519 - 16 Jan 2009
Cited by 37 | Viewed by 12418
Abstract
This work addresses a new configuration that improves the sensitivity of a humidity sensor based on a long-period fiber grating coated with a SiO2-nanospheres film. An intermediate higher refractive index overlay, deposited through Electrostatic Self-Assembly, is placed between the fiber cladding [...] Read more.
This work addresses a new configuration that improves the sensitivity of a humidity sensor based on a long-period fiber grating coated with a SiO2-nanospheres film. An intermediate higher refractive index overlay, deposited through Electrostatic Self-Assembly, is placed between the fiber cladding and the humidity sensitive film in order to increase the total effective refractive index of the coating. With this intermediate design, a three-fold improvement in the sensitivity was obtained. Wavelength shifts up to 15 nm against 5 nm were achieved in a humidity range from 20% to 80%. Full article
(This article belongs to the Special Issue Nanotechnological Advances in Biosensors)
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Review

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1639 KiB  
Review
Nanomaterials-Based Optical Techniques for the Detection of Acetylcholinesterase and Pesticides
by Ning Xia, Qinglong Wang and Lin Liu
Sensors 2015, 15(1), 499-514; https://doi.org/10.3390/s150100499 - 30 Dec 2014
Cited by 60 | Viewed by 10304
Abstract
The large amount of pesticide residues in the environment is a threat to global health by inhibition of acetylcholinesterase (AChE). Biosensors for inhibition of AChE have been thus developed for the detection of pesticides. In line with the rapid development of nanotechnology, nanomaterials [...] Read more.
The large amount of pesticide residues in the environment is a threat to global health by inhibition of acetylcholinesterase (AChE). Biosensors for inhibition of AChE have been thus developed for the detection of pesticides. In line with the rapid development of nanotechnology, nanomaterials have attracted great attention and have been intensively studied in biological analysis due to their unique chemical, physical and size properties. The aim of this review is to provide insight into nanomaterial-based optical techniques for the determination of AChE and pesticides, including colorimetric and fluorescent assays and surface plasmon resonance. Full article
(This article belongs to the Special Issue Nanotechnological Advances in Biosensors)
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437 KiB  
Review
Magnetic Nanoparticle Sensors
by Isaac Koh and Lee Josephson
Sensors 2009, 9(10), 8130-8145; https://doi.org/10.3390/s91008130 - 16 Oct 2009
Cited by 286 | Viewed by 23589
Abstract
Many types of biosensors employ magnetic nanoparticles (diameter = 5–300 nm) or magnetic particles (diameter = 300–5,000 nm) which have been surface functionalized to recognize specific molecular targets. Here we cover three types of biosensors that employ different biosensing principles, magnetic materials, and [...] Read more.
Many types of biosensors employ magnetic nanoparticles (diameter = 5–300 nm) or magnetic particles (diameter = 300–5,000 nm) which have been surface functionalized to recognize specific molecular targets. Here we cover three types of biosensors that employ different biosensing principles, magnetic materials, and instrumentation. The first type consists of magnetic relaxation switch assay-sensors, which are based on the effects magnetic particles exert on water proton relaxation rates. The second type consists of magnetic particle relaxation sensors, which determine the relaxation of the magnetic moment within the magnetic particle. The third type is magnetoresistive sensors, which detect the presence of magnetic particles on the surface of electronic devices that are sensitive to changes in magnetic fields on their surface. Recent improvements in the design of magnetic nanoparticles (and magnetic particles), together with improvements in instrumentation, suggest that magnetic material-based biosensors may become widely used in the future. Full article
(This article belongs to the Special Issue Nanotechnological Advances in Biosensors)
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661 KiB  
Review
Nanomaterial-Assisted Signal Enhancement of Hybridization for DNA Biosensors: A Review
by Jinhuai Liu, Jinyun Liu, Liangbao Yang, Xing Chen, Meiyun Zhang, Fanli Meng, Tao Luo and Minqiang Li
Sensors 2009, 9(9), 7343-7364; https://doi.org/10.3390/s90907343 - 11 Sep 2009
Cited by 47 | Viewed by 16167
Abstract
Detection of DNA sequences has received broad attention due to its potential applications in a variety of fields. As sensitivity of DNA biosensors is determined by signal variation of hybridization events, the signal enhancement is of great significance for improving the sensitivity in [...] Read more.
Detection of DNA sequences has received broad attention due to its potential applications in a variety of fields. As sensitivity of DNA biosensors is determined by signal variation of hybridization events, the signal enhancement is of great significance for improving the sensitivity in DNA detection, which still remains a great challenge. Nanomaterials, which possess some unique chemical and physical properties caused by nanoscale effects, provide a new opportunity for developing novel nanomaterial-based signal-enhancers for DNA biosensors. In this review, recent progress concerning this field, including some newly-developed signal enhancement approaches using quantum-dots, carbon nanotubes and their composites reported by our group and other researchers are comprehensively summarized. Reports on signal enhancement of DNA biosensors by non-nanomaterials, such as enzymes and polymer reagents, are also reviewed for comparison. Furthermore, the prospects for developing DNA biosensors using nanomaterials as signal-enhancers in future are also indicated. Full article
(This article belongs to the Special Issue Nanotechnological Advances in Biosensors)
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868 KiB  
Review
Semiconductor Quantum Dots in Chemical Sensors and Biosensors
by Manuela F. Frasco and Nikos Chaniotakis
Sensors 2009, 9(9), 7266-7286; https://doi.org/10.3390/s90907266 - 10 Sep 2009
Cited by 418 | Viewed by 29727
Abstract
Quantum dots are nanometre-scale semiconductor crystals with unique optical properties that are advantageous for the development of novel chemical sensors and biosensors. The surface chemistry of luminescent quantum dots has encouraged the development of multiple probes based on linked recognition molecules such as [...] Read more.
Quantum dots are nanometre-scale semiconductor crystals with unique optical properties that are advantageous for the development of novel chemical sensors and biosensors. The surface chemistry of luminescent quantum dots has encouraged the development of multiple probes based on linked recognition molecules such as peptides, nucleic acids or small-molecule ligands. This review overviews the design of sensitive and selective nanoprobes, ranging from the type of target molecules to the optical transduction scheme. Representative examples of quantum dot-based optical sensors from this fast-moving field have been selected and are discussed towards the most promising directions for future research. Full article
(This article belongs to the Special Issue Nanotechnological Advances in Biosensors)
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914 KiB  
Review
Optical Biosensors Based on Semiconductor Nanostructures
by Raúl J. Martín-Palma, Miguel Manso and Vicente Torres-Costa
Sensors 2009, 9(7), 5149-5172; https://doi.org/10.3390/s90705149 - 29 Jun 2009
Cited by 60 | Viewed by 15402
Abstract
The increasing availability of semiconductor-based nanostructures with novel and unique properties has sparked widespread interest in their use in the field of biosensing. The precise control over the size, shape and composition of these nanostructures leads to the accurate control of their physico-chemical [...] Read more.
The increasing availability of semiconductor-based nanostructures with novel and unique properties has sparked widespread interest in their use in the field of biosensing. The precise control over the size, shape and composition of these nanostructures leads to the accurate control of their physico-chemical properties and overall behavior. Furthermore, modifications can be made to the nanostructures to better suit their integration with biological systems, leading to such interesting properties as enhanced aqueous solubility, biocompatibility or bio-recognition. In the present work, the most significant applications of semiconductor nanostructures in the field of optical biosensing will be reviewed. In particular, the use of quantum dots as fluorescent bioprobes, which is the most widely used application, will be discussed. In addition, the use of some other nanometric structures in the field of biosensing, including porous semiconductors and photonic crystals, will be presented. Full article
(This article belongs to the Special Issue Nanotechnological Advances in Biosensors)
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1184 KiB  
Review
A Review on Direct Electrochemistry of Catalase for Electrochemical Sensors
by Periasamy Arun Prakash, Umasankar Yogeswaran and Shen-Ming Chen
Sensors 2009, 9(3), 1821-1844; https://doi.org/10.3390/s90301821 - 13 Mar 2009
Cited by 73 | Viewed by 19814
Abstract
Catalase (CAT) is a heme enzyme with a Fe(III/II) prosthetic group at its redox centre. CAT is present in almost all aerobic living organisms, where it catalyzes the disproportionation of H2O2 into oxygen and water without forming free radicals. [...] Read more.
Catalase (CAT) is a heme enzyme with a Fe(III/II) prosthetic group at its redox centre. CAT is present in almost all aerobic living organisms, where it catalyzes the disproportionation of H2O2 into oxygen and water without forming free radicals. In order to study this catalytic mechanism in detail, the direct electrochemistry of CAT has been investigated at various modified electrode surfaces with and without nanomaterials. The results show that CAT immobilized on nanomaterial modified electrodes shows excellent catalytic activity, high sensitivity and the lowest detection limit for H2O2 determination. In the presence of nanomaterials, the direct electron transfer between the heme group of the enzyme and the electrode surface improved significantly. Moreover, the immobilized CAT is highly biocompatible and remains extremely stable within the nanomaterial matrices. This review discusses about the versatile approaches carried out in CAT immobilization for direct electrochemistry and electrochemical sensor development aimed as efficient H2O2 determination. The benefits of immobilizing CAT in nanomaterial matrices have also been highlighted. Full article
(This article belongs to the Special Issue Nanotechnological Advances in Biosensors)
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718 KiB  
Review
Applications of Nanomaterials in Electrogenerated Chemiluminescence Biosensors
by Honglan Qi, Yage Peng, Qiang Gao and Chengxiao Zhang
Sensors 2009, 9(1), 674-695; https://doi.org/10.3390/s90100674 - 23 Jan 2009
Cited by 105 | Viewed by 16396
Abstract
Electrogenerated chemiluminescence (also called electrochemiluminescence and abbreviated ECL) involves the generation of species at electrode surfaces that then undergo electron-transfer reactions to form excited states that emit light. ECL biosensor, combining advantages offered by the selectivity of the biological recognition elements and the [...] Read more.
Electrogenerated chemiluminescence (also called electrochemiluminescence and abbreviated ECL) involves the generation of species at electrode surfaces that then undergo electron-transfer reactions to form excited states that emit light. ECL biosensor, combining advantages offered by the selectivity of the biological recognition elements and the sensitivity of ECL technique, is a powerful device for ultrasensitive biomolecule detection and quantification. Nanomaterials are of considerable interest in the biosensor field owing to their unique physical and chemical properties, which have led to novel biosensors that have exhibited high sensitivity and stability. Nanomaterials including nanoparticles and nanotubes, prepared from metals, semiconductor, carbon or polymeric species, have been widely investigated for their ability to enhance the efficiencies of ECL biosensors, such as taking as modification electrode materials, or as carrier of ECL labels and ECL-emitting species. Particularly useful application of nanomaterials in ECL biosensors with emphasis on the years 2004-2008 is reviewed. Remarks on application of nanomaterials in ECL biosensors are also surveyed. Full article
(This article belongs to the Special Issue Nanotechnological Advances in Biosensors)
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