Chemosensors

23 pages, 8362 KiB

Open AccessReview

Recent Advances of Fluorescence Probes for Imaging of Ferroptosis Process

by Hongyu Li, Yan An, Jie Gao, Mingyan Yang, Junjun Luo, Xinmin Li, Jiajia Lv, Xiaohua Li, Zeli Yuan and Huimin Ma

Chemosensors 2022, 10(6), 233; https://doi.org/10.3390/chemosensors10060233 - 20 Jun 2022

Cited by 19 | Viewed by 3495

Abstract

Ferroptosis is an iron−dependent form of regulated cell death. It has attracted more and more research interests since it was found because of its potential physiological and pathological roles. In recent years, many efforts have been made for the developments and applications of [...] Read more.

Ferroptosis is an iron−dependent form of regulated cell death. It has attracted more and more research interests since it was found because of its potential physiological and pathological roles. In recent years, many efforts have been made for the developments and applications of selective fluorescence probes for real−time and in situ tracking of bioactive species during ferroptosis process, which is necessary and significant to further study the modulation mechanisms and pathological functions of ferroptosis. In this review, we will focus on summarizing the newly developed fluorescence probes that have been applied for ferroptosis imaging in the recent years, and comprehensively discussing their design strategies, including the probes for iron, reactive oxygen species, biothiols and intracellular microenvironmental factors. Full article

(This article belongs to the Special Issue Chemical and Biosensors: A Theme Issue in Honor of Professor Otto S. Wolfbeis)

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16 pages, 2645 KiB

Open AccessArticle

Optical Chemical Sensor Based on Fast-Protein Liquid Chromatography for Regular Peritoneal Protein Loss Assessment in End-Stage Renal Disease Patients on Continuous Ambulatory Peritoneal Dialysis

by Artur Kuznetsov, Aleksandr Frorip, Alar Sünter, Vadim Korsakov, Georgii Konoplev, Oksana Stepanova, Natalia Roschina, Nikolay Ovsyannikov, Daniil Lialin, Roman Gerasimchuk, Alexander Dmitriev, Nikolay Mukhin and Soeren Hirsch

Chemosensors 2022, 10(6), 232; https://doi.org/10.3390/chemosensors10060232 - 17 Jun 2022

Cited by 6 | Viewed by 2388

Abstract

Point-of-care testing (POCT) devices are becoming increasingly popular in the medical community as an alternative to conventional laboratory testing, especially for home treatments or other forms of outpatient care. Multiple-use chemical sensors with minimal requirements for disposables are among the most practical and [...] Read more.

Point-of-care testing (POCT) devices are becoming increasingly popular in the medical community as an alternative to conventional laboratory testing, especially for home treatments or other forms of outpatient care. Multiple-use chemical sensors with minimal requirements for disposables are among the most practical and cost-effective POC diagnostic instruments, especially in managing chronic conditions. An affordable, simple, and easy-to-use optical sensor based on fast protein liquid chromatography with direct UV absorption detection was developed for the rapid determination of the total protein concentration in effluent peritoneal dialysate and for the assessment of protein losses in end-stage renal disease (ESRD) patients on constant ambulatory peritoneal dialysis (CAPD). The sensor employs non-disposable PD-10 desalting columns for the separation of molecules with different molecular weights and a deep UV LED (maximum at 285 nm) as a light source for optical detection. The analytic procedure is relatively simple, takes 10–15 min, and potentially can be performed by patients themselves or nursing staff without laboratory training. Preliminary clinical trials on a group of 23 patients on CAPD revealed a good concordance between the protein concentrations in dialysate samples measured with the sensor and an automated biochemical analyzer; the mean relative error was about 10%, which is comparable with routine clinical laboratory methods. Full article

(This article belongs to the Section Optical Chemical Sensors)

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31 pages, 10422 KiB

Open AccessReview

Metal Oxide Semiconductor Sensors for Triethylamine Detection: Sensing Performance and Improvements

by Hua Zhang, Yinghao Guo and Fanli Meng

Chemosensors 2022, 10(6), 231; https://doi.org/10.3390/chemosensors10060231 - 17 Jun 2022

Cited by 32 | Viewed by 4999

Abstract

Triethylamine (TEA) is an organic compound that is commonly used in industries, but its volatile, inflammable, corrosive, and toxic nature leads to explosions and tissue damage. A sensitive, accurate, and in situ monitoring of TEA is of great significance to production safety and [...] Read more.

Triethylamine (TEA) is an organic compound that is commonly used in industries, but its volatile, inflammable, corrosive, and toxic nature leads to explosions and tissue damage. A sensitive, accurate, and in situ monitoring of TEA is of great significance to production safety and human health. Metal oxide semiconductors (MOSs) are widely used as gas sensors for volatile organic compounds due to their high bandgap and unique microstructure. This review aims to provide insights into the further development of MOSs by generalizing existing MOSs for TEA detection and measures to improve their sensing performance. This review starts by proposing the basic gas-sensing characteristics of the sensor and two typical TEA sensing mechanisms. Then, recent developments to improve the sensing performance of TEA sensors are summarized from different aspects, such as the optimization of material morphology, the incorporation of other materials (metal elements, conducting polymers, etc.), the development of new materials (graphene, TMDs, etc.), the application of advanced fabrication devices, and the introduction of external stimulation. Finally, this review concludes with prospects for using the aforementioned methods in the fabrication of high-performance TEA gas sensors, as well as highlighting the significance and research challenges in this emerging field. Full article

(This article belongs to the Special Issue Chemical Sensors for Volatile Organic Compound Detection)

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16 pages, 4370 KiB

Open AccessArticle

Promising Novel Barium Carbonate One-Dimensional Nanostructures and Their Gas Sensing Application: Preparation and Characterization

by Nagih M. Shaalan

Chemosensors 2022, 10(6), 230; https://doi.org/10.3390/chemosensors10060230 - 17 Jun 2022

Viewed by 2261

Abstract

Recently, barium carbonate-based nanomaterials have been used for sensor and catalysis applications. The sensing performance can be improved with a suitable one-dimensional nanostructure. In this regard, novel nanosized BaCO₃ materials were fabricated by a one-pot designed thermal evaporation system. Ten milligrams of [...] Read more.

Recently, barium carbonate-based nanomaterials have been used for sensor and catalysis applications. The sensing performance can be improved with a suitable one-dimensional nanostructure. In this regard, novel nanosized BaCO₃ materials were fabricated by a one-pot designed thermal evaporation system. Ten milligrams of Ba as raw material were used to deposit BaCO₃ nanostructures at a pressure of 0.85 torr and a temperature of 850 °C in a partial oxygen atmosphere of the ambient. This simple method for fabricating novel BaCO₃ nanostructures is presented here. X-ray diffraction was indexed on the orthorhombic polycrystalline structure of the prepared BaCO₃. The nanostructures deposited here could be described as Datura-like structures linked with nanowires of 20–50 nm in diameter and 5 µm in length. The BaCO₃ nanostructure prepared by the current method exhibited a semiconductor-like behavior with an activation energy of 0.68 eV. This behavior was ascribed to the nature of the morphology, which may possess large defective points. Thus, this nanostructure was subjected to gas sensing measurements, showing high activity toward NO₂ gas. The proposed sensor also underwent deep investigation toward NO₂ at various gas concentrations and working. The response and recovery time constants were recorded in the ranges of 6–20 s and 30–150 s, respectively. The sensor showed its reversibility toward NO₂ when the sensor signal was repeated at various cycles of various concentrations. The sensor was exposed to different levels of humidity, showing high performance toward NO₂ gas at 250 °C. The sensor exhibited fast response and recovery toward NO₂ gas. Full article

(This article belongs to the Topic Synthesis and Applications of Nanostructured Metals and Metal Oxides)

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19 pages, 1714 KiB

Open AccessArticle

Extraction of Reduced Infrared Biomarker Signatures for the Stratification of Patients Affected by Parkinson’s Disease: An Untargeted Metabolomic Approach

by Kateryna Tkachenko, María Espinosa, Isabel Esteban-Díez, José M. González-Sáiz and Consuelo Pizarro

Chemosensors 2022, 10(6), 229; https://doi.org/10.3390/chemosensors10060229 - 16 Jun 2022

Cited by 2 | Viewed by 2219

Abstract

An untargeted Fourier transform infrared (FTIR) metabolomic approach was employed to study metabolic changes and disarrangements, recorded as infrared signatures, in Parkinson’s disease (PD). Herein, the principal aim was to propose an efficient sequential classification strategy based on SELECT-LDA, which enabled optimal stratification [...] Read more.

An untargeted Fourier transform infrared (FTIR) metabolomic approach was employed to study metabolic changes and disarrangements, recorded as infrared signatures, in Parkinson’s disease (PD). Herein, the principal aim was to propose an efficient sequential classification strategy based on SELECT-LDA, which enabled optimal stratification of three main categories: PD patients from subjects with Alzheimer’s disease (AD) and healthy controls (HC). Moreover, sub-categories, such as PD at the early stage (PDI) from PD in the advanced stage (PDD), and PDD vs. AD, were stratified. Every classification step with selected wavenumbers achieved 90.11% to 100% correct assignment rates in classification and internal validation. Therefore, selected metabolic signatures from new patients could be used as input features for screening and diagnostic purposes. Full article

(This article belongs to the Special Issue Analytical and Computational Systems in Biosensing)

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18 pages, 1928 KiB

Open AccessReview

Temperature Sensors Based on Polymer Fiber Optic Interferometer

by Malgorzata Szczerska

Chemosensors 2022, 10(6), 228; https://doi.org/10.3390/chemosensors10060228 - 15 Jun 2022

Cited by 19 | Viewed by 3685

Abstract

Temperature measurements are of great importance in many fields of human activities, including industry, technology, and science. For example, obtaining a certain temperature value or a sudden change in it can be the primary control marker of a chemical process. Fiber optic sensors [...] Read more.

Temperature measurements are of great importance in many fields of human activities, including industry, technology, and science. For example, obtaining a certain temperature value or a sudden change in it can be the primary control marker of a chemical process. Fiber optic sensors have remarkable properties giving a broad range of applications. They enable continuous real-time temperature control in difficult-to-reach areas, in hazardous working environments (air pollution, chemical or ionizing contamination), and in the presence of electromagnetic disturbances. The use of fiber optic temperature sensors in polymer technology can significantly reduce the cost of their production. Moreover, the installation process and usage would be simplified. As a result, these types of sensors would become increasingly popular in industrial solutions. This review provides a critical overview of the latest development of fiber optic temperature sensors based on Fabry–Pérot interferometer made with polymer technology. Full article

(This article belongs to the Special Issue Polymer Based Chemosensors)

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29 pages, 6262 KiB

Open AccessReview

High-Performance Room-Temperature Conductometric Gas Sensors: Materials and Strategies

by Antonio Vázquez-López, Javier Bartolomé, Ana Cremades and David Maestre

Chemosensors 2022, 10(6), 227; https://doi.org/10.3390/chemosensors10060227 - 15 Jun 2022

Cited by 13 | Viewed by 3629

Abstract

Chemiresistive sensors have gained increasing interest in recent years due to the necessity of low-cost, effective, high-performance gas sensors to detect volatile organic compounds (VOC) and other harmful pollutants. While most of the gas sensing technologies rely on the use of high operation [...] Read more.

Chemiresistive sensors have gained increasing interest in recent years due to the necessity of low-cost, effective, high-performance gas sensors to detect volatile organic compounds (VOC) and other harmful pollutants. While most of the gas sensing technologies rely on the use of high operation temperatures, which increase usage cost and decrease efficiency due to high power consumption, a particular subset of gas sensors can operate at room temperature (RT). Current approaches are aimed at the development of high-sensitivity and multiple-selectivity room-temperature sensors, where substantial research efforts have been conducted. However, fewer studies presents the specific mechanism of action on why those particular materials can work at room temperature and how to both enhance and optimize their RT performance. Herein, we present strategies to achieve RT gas sensing for various materials, such as metals and metal oxides (MOs), as well as some of the most promising candidates, such as polymers and hybrid composites. Finally, the future promising outlook on this technology is discussed. Full article

(This article belongs to the Special Issue Low-Cost Chemo/Bio-Sensors Based on Nanomaterials)

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13 pages, 3950 KiB

Open AccessArticle

Dynamic Measurement of VOCs with Multiple Characteristic Peaks Based on Temperature Modulation of ZnO Gas Sensor

by Xue Shi, Hua Zhang, Hanyang Ji and Fanli Meng

Chemosensors 2022, 10(6), 226; https://doi.org/10.3390/chemosensors10060226 - 15 Jun 2022

Cited by 4 | Viewed by 2159

Abstract

Volatile organic compounds (VOC) harm human health seriously in the air. Therefore, it is essential to recognize VOC gases qualitatively and quantitatively. The dynamic measurement method can improve the selectivity of metal oxide semiconductor (MOS) gas sensors to VOC, but there is a [...] Read more.

Volatile organic compounds (VOC) harm human health seriously in the air. Therefore, it is essential to recognize VOC gases qualitatively and quantitatively. The dynamic measurement method can improve the selectivity of metal oxide semiconductor (MOS) gas sensors to VOC, but there is a problem of the insufficient number of characteristic peaks. From the experimental point of view, the primary judgment basis for the correct qualitative and quantitative recognition of VOC gases by the dynamic measurement method is the characteristic peak of the dynamic response signal. However, the traditional dynamic measurement method generally only has two characteristic peaks. In this experiment, the voltage was changed at the time of the second characteristic peak by controlling the constant dynamic response period. Taking ethyl alcohol as an example, the experimental results show that the characteristic peak of the dynamic response signal does not increase when the voltage is constant. However, a new characteristic peak will appear based on a continuously rising heating voltage. The characteristic peaks of the dynamic response of n-propyl alcohol, isopropyl alcohol, and n-butyl alcohol were also increased based on the rising heating voltage waveform. Based on the K-Nearest-Neighbors algorithm, the qualitative and quantitative recognition rate of the four alcohol homologue gases reached 100%. Full article

(This article belongs to the Special Issue Chemical Sensors for Volatile Organic Compound Detection)

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13 pages, 3095 KiB

Open AccessArticle

Fabrication and Magneto-Structural Properties of Co₂-Based Heusler Alloy Glass-Coated Microwires with High Curie Temperature

by Mohamed Salaheldeen, Alfonso Garcia-Gomez, Mihail Ipatov, Paula Corte-Leon, Valentina Zhukova, Juan Maria Blanco and Arcady Zhukov

Chemosensors 2022, 10(6), 225; https://doi.org/10.3390/chemosensors10060225 - 14 Jun 2022

Cited by 14 | Viewed by 2696

Abstract

In this work, we were able to produce Co₂FeSi Heusler alloy glass-covered microwires with a metallic nucleus diameter of about 4.4 µm and total sample diameter of about 17.6 μm by the Taylor–Ulitovsky Technique. This low cost and single step fabrication [...] Read more.

In this work, we were able to produce Co₂FeSi Heusler alloy glass-covered microwires with a metallic nucleus diameter of about 4.4 µm and total sample diameter of about 17.6 μm by the Taylor–Ulitovsky Technique. This low cost and single step fabrication process allowed the preparation of up to kilometers long glass-coated microwires starting from a few grams of high purity inexpensive elements (Co, Fe and Si), for a wide range of applications. From the X-ray diffraction, XRD, analysis of the metallic nucleus, it was shown that the structure consists of a mixture of crystalline and amorphous phases. The single and wide crystalline peak was attributed to a L2₁ crystalline structure (5.640 Å), with a possible B2 disorder. In addition, nanocrystalline structure with an average grain size, D_g = 17.8 nm, and crystalline phase content of about 52% was obtained. The magnetic measurements indicated a well-defined magnetic anisotropy for all ranges of temperature. Moreover, soft magnetic behavior was observed for the temperature measuring range of 5–1000 K. Strong dependence of the magnetic properties on the applied magnetic field and temperature was observed. Zero field cooling and field cooling magnetization curves showed large irreversibility magnetic behavior with a blocking temperature (T_B = 205 K). The in-plane magnetization remanence and coercivity showed quite different behavior with temperature, due to the existence of different magnetic phases induced from the internal stress created by the glass-coated layer. Moreover, a high Curie temperature was reported (T_c ≈ 1059 K), which predisposes this material to being a suitable candidate for high temperature spintronic applications. Full article

(This article belongs to the Special Issue Innovative Materials, Technologies, and Sensors)

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15 pages, 1083 KiB

Open AccessArticle

Noise Spectrum as a Source of Information in Gas Sensors Based on Liquid-Phase Exfoliated Graphene

by Stevan Andrić, Ivana Jokić, Jelena Stevanović, Marko Spasenović and Miloš Frantlović

Chemosensors 2022, 10(6), 224; https://doi.org/10.3390/chemosensors10060224 - 14 Jun 2022

Cited by 1 | Viewed by 2018

Abstract

Surfaces of adsorption-based gas sensors are often heterogeneous, with adsorption sites that differ in their affinities for gas particle binding. Knowing adsorption/desorption energies, surface densities and the relative abundance of sites of different types is important, because these parameters impact sensor sensitivity and [...] Read more.

Surfaces of adsorption-based gas sensors are often heterogeneous, with adsorption sites that differ in their affinities for gas particle binding. Knowing adsorption/desorption energies, surface densities and the relative abundance of sites of different types is important, because these parameters impact sensor sensitivity and selectivity, and are relevant for revealing the response-generating mechanisms. We show that the analysis of the noise of adsorption-based sensors can be used to study gas adsorption on heterogeneous sensing surfaces, which is applicable to industrially important liquid-phase exfoliated (LPE) graphene. Our results for CO₂ adsorption on an LPE graphene surface, with different types of adsorption sites on graphene flake edges and basal planes, show that the noise spectrum data can be used to characterize such surfaces in terms of parameters that determine the sensing properties of the adsorbing material. Notably, the spectrum characteristic frequencies are an unambiguous indicator of the relative abundance of different types of adsorption sites on the sensing surface and their surface densities. We also demonstrate that spectrum features indicate the fraction of the binding sites that are already occupied by another gas species. The presented study can be applied to the design and production of graphene and other sensing surfaces with an optimal sensing performance. Full article

(This article belongs to the Special Issue 2D Materials for Gas Sensing)

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25 pages, 5448 KiB

Open AccessReview

Recent Trends in Carbon Nanotube Electrodes for Flexible Supercapacitors: A Review of Smart Energy Storage Device Assembly and Performance

by Himadri Tanaya Das, Swapnamoy Dutta, Tamilarasan Elango Balaji, Nigamananda Das, Payaswini Das, Neelu Dheer, Rajni Kanojia, Preety Ahuja and Sanjeev Kumar Ujjain

Chemosensors 2022, 10(6), 223; https://doi.org/10.3390/chemosensors10060223 - 13 Jun 2022

Cited by 39 | Viewed by 4301

Abstract

In order to upgrade existing electronic technology, we need simultaneously to advance power supply devices to match emerging requirements. Owing to the rapidly growing wearable and portable electronics markets, the demand to develop flexible energy storage devices is among the top priorities for [...] Read more.

In order to upgrade existing electronic technology, we need simultaneously to advance power supply devices to match emerging requirements. Owing to the rapidly growing wearable and portable electronics markets, the demand to develop flexible energy storage devices is among the top priorities for humankind. Flexible supercapacitors (FSCs) have attracted tremendous attention, owing to their unrivaled electrochemical performances, long cyclability and mechanical flexibility. Carbon nanotubes (CNTs), long recognized for their mechanical toughness, with an elastic strain limit of up to 20%, are regarded as potential candidates for FSC electrodes. Along with excellent mechanical properties, high electrical conductivity, and large surface area, their assemblage adaptability from one-dimensional fibers to two-dimensional films to three-dimensional sponges makes CNTs attractive. In this review, we have summarized various assemblies of CNT structures, and their involvement in various device configurations of FSCs. Furthermore, to present a clear scenario of recent developments, we discuss the electrochemical performance of fabricated flexible devices of different CNT structures and their composites, including additional properties such as compressibility and stretchability. Additionally, the drawbacks and benefits of the study and further potential scopes are distinctly emphasized for future researchers. Full article

(This article belongs to the Special Issue Flexible Sensors and Supercapacitors Based on Carbon Nanotubes and Graphene)

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12 pages, 3075 KiB

Open AccessCommunication

Differential Sensing of Antibiotics Using Metal Ions and Gold Nanoclusters Based on TMB–H₂O₂ System

by Suqin Liu, Jinjie Wang, Yue Hu, Yunjing Shi, Jingxia Yang and Min Zhang

Chemosensors 2022, 10(6), 222; https://doi.org/10.3390/chemosensors10060222 - 12 Jun 2022

Cited by 2 | Viewed by 2548

Abstract

In the water system, antibiotic pollution significantly impacts the human body and the environment. Therefore, it is essential to quickly identify the types of antibiotics in the system and detect their concentration. It has been reported that many metal ions interact with antibiotics, [...] Read more.

In the water system, antibiotic pollution significantly impacts the human body and the environment. Therefore, it is essential to quickly identify the types of antibiotics in the system and detect their concentration. It has been reported that many metal ions interact with antibiotics, and some of them can also change the enzyme-like catalytic properties of gold clusters (AuNCs). In the experiments, we found significant differences in the experimental results when different antibiotics and metal ions were placed in a TMB-H₂O₂ system with AuNCs as catalysts. Based on this result, we devised a simple and sensitive colorimetric method for the simultaneous detection of multiple antibiotics using AuNCs-metal ions as the sensor, a multifunctional microplate detector as the detection instrument, and LDA as the analytical method. This method was successfully applied for the identification of antibiotics and the detection of their concentrations in river water. Full article

(This article belongs to the Section Analytical Methods, Instrumentation and Miniaturization)

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17 pages, 1629 KiB

Open AccessReview

SARS-CoV-2 Detection Methods

by Alexandra Lino, Marita A. Cardoso, Helena M. R. Gonçalves and Paula Martins-Lopes

Chemosensors 2022, 10(6), 221; https://doi.org/10.3390/chemosensors10060221 - 11 Jun 2022

Cited by 14 | Viewed by 3815

Abstract

A fast and highly specific detection of COVID-19 infections is essential in managing the virus dissemination networks. The most relevant technologies developed for SARS-CoV-2 detection, along with their advantages and limitations, will be presented and fully explored. Additionally, some of the newest and [...] Read more.

A fast and highly specific detection of COVID-19 infections is essential in managing the virus dissemination networks. The most relevant technologies developed for SARS-CoV-2 detection, along with their advantages and limitations, will be presented and fully explored. Additionally, some of the newest and emerging COVID-19 diagnosis tools, such as biosensing platforms, will also be introduced. Considering the extreme relevance that all these technologies assume in pandemic control, it is of the utmost relevance to have an intrinsic knowledge of the parameters that need to be taken into consideration before choosing the most adequate test for a particular situation. Moreover, the new variants of the virus and their potential impact on the detection method’s effectiveness will be discussed. In order to better manage the pandemic, it is essential to maintain continuous research into the SARS-CoV-2 genome and updated genomic surveillance at the global level. This will allow for timely detection of new mutations and viral variants, which may affect the performance of COVID-19 detection tests. Full article

(This article belongs to the Special Issue State of the Art in Nucleic Acid Detection)

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13 pages, 3048 KiB

Open AccessArticle

Classification of Aviation Alloys Using Laser-Induced Breakdown Spectroscopy Based on a WT-PSO-LSSVM Model

by Haorong Guo, Minchao Cui, Zhongqi Feng, Dacheng Zhang and Dinghua Zhang

Chemosensors 2022, 10(6), 220; https://doi.org/10.3390/chemosensors10060220 - 10 Jun 2022

Cited by 8 | Viewed by 2053

Abstract

It is well-known that aviation alloys of different grades show large differences in mechanical properties. At present, alloys must be strictly distinguished in the manufacturing plant because their close appearance and density are easily confused In this work, the wavelet transform (WT) method [...] Read more.

It is well-known that aviation alloys of different grades show large differences in mechanical properties. At present, alloys must be strictly distinguished in the manufacturing plant because their close appearance and density are easily confused In this work, the wavelet transform (WT) method combined with the least squares support vector machine (LSSVM) is applied to the classification and identification of aviation alloys by laser-induced breakdown spectroscopy (LIBS). This experiment employed six different grades of aviation alloy as the classification samples and obtained 100 sets of spectral data for each sample. This research included the steps of preprocessing the obtained spectral data, model training, and parameter optimization. Finally, the accuracy of the training set was 99.98%, and the accuracy of the test set was 99.56%. Therefore, it is concluded that the model has superior generalization capacity and portability. The result of this work illustrates that LIBS technology can be adopted for the rapid identification of aviation alloys, which is of great significance for on-site quality control and efficiency improvement of aerospace parts manufacturing. Full article

(This article belongs to the Special Issue Application of Laser-Induced Breakdown Spectroscopy)

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13 pages, 3587 KiB

Open AccessArticle

Folic Acid-Modified Cerium-Doped Carbon Dots as Photoluminescence Sensors for Cancer Cells Identification and Fe(III) Detection

by Jincheng Li, Zengchao Guo, Tengfei Liu, Fangfang Yu, Jiayu Zeng, Ying Zhang, Lihong Yin, Xiaohui Liu, Hui Jiang and Xuemei Wang

Chemosensors 2022, 10(6), 219; https://doi.org/10.3390/chemosensors10060219 - 9 Jun 2022

Cited by 11 | Viewed by 3069

Abstract

Carbon dots (CDs) are a new class of carbon-based luminescence materials with fascinating properties. They have been given great expectations on superseding traditional semiconductor quantum dots due to their good dispersity and stability, relatively low toxicity, superior resistance to photobleaching, and excellent biocompatibility. [...] Read more.

Carbon dots (CDs) are a new class of carbon-based luminescence materials with fascinating properties. They have been given great expectations on superseding traditional semiconductor quantum dots due to their good dispersity and stability, relatively low toxicity, superior resistance to photobleaching, and excellent biocompatibility. The diversified luminescence properties of CDs are largely due to the synthetic strategies and precursors. In view of those described above, this study has explored the possibility to establish a facile one-step hydrothermal method for the one-pot synthesis of folic acid-modified cerium-doped CDs (Ce-CDs-FA), which could be further utilized as a sensitive fluorescent nanoprobe for biosensing. This investigation demonstrates that the Ce-CDs-FA nanocomposites have nice biocompatibility and bright fluorescent properties, which can be readily utilized to detect cancer cells through recognizing overexpressing folate receptors by virtue of folic acid. Meanwhile, it is noted that the Fe³⁺ ion can actualize a specific and hypersensitive quenching effect for these Ce-CDs-FA nanocomposites, which can be further explored for special ion recognition, including iron ions. It raises the possibility that the as-prepared Ce-CDs-FA nanocomposites could be extended as a dual fluorescence sensor for targeted cell imaging and Fe³⁺ ion detection. Full article

(This article belongs to the Special Issue Application of Luminescent Materials for Sensing)

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17 pages, 3056 KiB

Open AccessArticle

Detection of Acetoin and Diacetyl by a Tobacco Mosaic Virus-Assisted Field-Effect Biosensor

by Melanie Welden, Robin Severins, Arshak Poghossian, Christina Wege, Johannes Bongaerts, Petra Siegert, Michael Keusgen and Michael J. Schöning

Chemosensors 2022, 10(6), 218; https://doi.org/10.3390/chemosensors10060218 - 8 Jun 2022

Cited by 7 | Viewed by 2672

Abstract

Acetoin and diacetyl have a major impact on the flavor of alcoholic beverages such as wine or beer. Therefore, their measurement is important during the fermentation process. Until now, gas chromatographic techniques have typically been applied; however, these require expensive laboratory equipment and [...] Read more.

Acetoin and diacetyl have a major impact on the flavor of alcoholic beverages such as wine or beer. Therefore, their measurement is important during the fermentation process. Until now, gas chromatographic techniques have typically been applied; however, these require expensive laboratory equipment and trained staff, and do not allow for online monitoring. In this work, a capacitive electrolyte–insulator–semiconductor sensor modified with tobacco mosaic virus (TMV) particles as enzyme nanocarriers for the detection of acetoin and diacetyl is presented. The enzyme acetoin reductase from Alkalihalobacillus clausii DSM 8716^T is immobilized via biotin–streptavidin affinity, binding to the surface of the TMV particles. The TMV-assisted biosensor is electrochemically characterized by means of leakage–current, capacitance–voltage, and constant capacitance measurements. In this paper, the novel biosensor is studied regarding its sensitivity and long-term stability in buffer solution. Moreover, the TMV-assisted capacitive field-effect sensor is applied for the detection of diacetyl for the first time. The measurement of acetoin and diacetyl with the same sensor setup is demonstrated. Finally, the successive detection of acetoin and diacetyl in buffer and in diluted beer is studied by tuning the sensitivity of the biosensor using the pH value of the measurement solution. Full article

(This article belongs to the Special Issue Nanostructured Devices for Biochemical Sensing)

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15 pages, 4993 KiB

Open AccessArticle

A Plankton Detection Method Based on Neural Networks and Digital Holographic Imaging

by Kaiqi Lang, Hui Cai and Xiaoping Wang

Chemosensors 2022, 10(6), 217; https://doi.org/10.3390/chemosensors10060217 - 8 Jun 2022

Cited by 1 | Viewed by 2106

Abstract

Detecting marine plankton by means of digital holographic microscopy (DHM) has been successfully deployed in recent decades; however, in most previous studies, the identification of the position, shape, and size of plankton has been neglected, which may negate some of the advantages of [...] Read more.

Detecting marine plankton by means of digital holographic microscopy (DHM) has been successfully deployed in recent decades; however, in most previous studies, the identification of the position, shape, and size of plankton has been neglected, which may negate some of the advantages of DHM. Therefore, the procedure of image fusion has been added between the reconstruction of initial holograms and the final identification, which could help present all the images of plankton clearly in a volume of seawater. A new image fusion method called digital holographic microscopy-fully convolutional networks (DHM-FCN) is proposed, which is based on the improved fully convolutional networks (FCN). The DHM-FCN model runs 20 times faster than traditional image fusion methods and suppresses the noise in the holograms. All plankton in a 2 mm thick water body could be clearly represented in the fusion image. The edges of the plankton in the DHM-FCN fusion image are continuous and clear without speckle noise inside. The neural network model, YOLOv4, for plankton identification and localization, was established. A mean average precision (mAP) of 97.69% was obtained for five species, Alexandrium tamarense, Chattonella marina, Mesodinium rubrum, Scrippsiella trochoidea, and Prorocentrum lima. The results of this study could provide a fast image fusion method and a visual method to detect organisms in water. Full article

(This article belongs to the Section Applied Chemical Sensors)

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10 pages, 2380 KiB

Open AccessArticle

Deep Eutectic Solvents Enhance Stability of Ag/AgCl Solid State Miniaturised Reference Electrode

by Sahar S. M. Alabdullah, Amina M. Abass and Huda Ghalib Salman

Chemosensors 2022, 10(6), 216; https://doi.org/10.3390/chemosensors10060216 - 7 Jun 2022

Cited by 4 | Viewed by 2200

Abstract

A new class of solid-state miniaturised reference electrodes with a deep eutectic solvent as an alternate enhancement electrode system is described. A simple and accurate stable electrochemical sensor was prepared by developing a conventional reference electrode using an Ag/AgCl planar micro-reference electrode covered [...] Read more.

A new class of solid-state miniaturised reference electrodes with a deep eutectic solvent as an alternate enhancement electrode system is described. A simple and accurate stable electrochemical sensor was prepared by developing a conventional reference electrode using an Ag/AgCl planar micro-reference electrode covered with a PVC polymer. A conductive deep eutectic solvent (DES), ethaline, was added in small quantities and mixed with an internal electrolyte to maintain the Cl⁻ ion concentration in the constructed electrode. The fabricated microelectrode showed good stability, reproducibility, and long-term stability against varying concentrations of different ions. The potential response of the fabricated microelectrode was studied under varying concentrations of Cl⁻ ions in the presence of 0.1 to 1.0% DES in a concentrated electrolyte system (20 mM Na₂SO₄). The stability of the fabricated microelectrode was addressed against Br⁻ and Cl⁻ ions using different inorganic salts, and the potential measurements were found to be insensitive toward all responsive ions. The stability response of the fabricated microelectrode against Cl⁻ ions was optimised in the presence of 1.0% DES. The experimental data showed good agreement with the potential change of the fabricated electrode in the presence of the supporting DES electrolyte. The liquid junction-free PVC solid-state miniaturised reference electrode demonstrated a constant potentiometric measurement over a long period of time. The concentrated supporting DES electrolyte solution (20 mM) exhibited better stability values and was a more suitable fabricated microelectrode than other additive concentrations. The long-term stability of the developed microelectrode displayed a good lifetime and high stability of around 60 days. Full article

(This article belongs to the Section Electrochemical Devices and Sensors)

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18 pages, 2372 KiB

Open AccessArticle

Detecting the Bitterness of Milk-Protein-Derived Peptides Using an Electronic Tongue

by Arijit Nath, Burak Atilla Eren, John-Lewis Zinia Zaukuu, András Koris, Klára Pásztorné-Huszár, Emőke Szerdahelyi and Zoltan Kovacs

Chemosensors 2022, 10(6), 215; https://doi.org/10.3390/chemosensors10060215 - 7 Jun 2022

Cited by 10 | Viewed by 3951

Abstract

Bitterness is a considerable limiting factor for the application of bioactive peptides in the food industry. The objective of this study was to compare the level of bitterness of milk-protein-derived peptides using an electronic tongue (E-tongue). Liquid milk protein concentrate (LMPC) was prepared [...] Read more.

Bitterness is a considerable limiting factor for the application of bioactive peptides in the food industry. The objective of this study was to compare the level of bitterness of milk-protein-derived peptides using an electronic tongue (E-tongue). Liquid milk protein concentrate (LMPC) was prepared from ultra-heat-treated skimmed cow’s milk. It was initially hydrolyzed with different concentrations of trypsin, namely, 0.008 g·L⁻¹, 0.016 g·L⁻¹ and 0.032 g·L⁻¹. In a later exercise, tryptic-hydrolyzed LMPC (LMPC-T) was further hydrolyzed using Lactobacillus bulgaricus and Streptococcus thermophilus. The effect of glucose in microbial hydrolysis was studied. The bitterness of peptides was evaluated with respect to quinine, a standard bittering agent. The level of bitterness of the peptides after microbial hydrolysis of LMPC-T (LMPC-T-F and LMPC-T-F_G) was evaluated using a potentiometric E-tongue equipped with a sensor array that had seven chemically modified field-effect transistor sensors. The results of the measurements were evaluated using principal component analysis (PCA), and subsequently, a classification of the models was built using the linear discriminant analysis (LDA) method. The bitterness of peptides in LMPC-T-F and LMPC-T-F_G was increased with the increase in the concentration of trypsin. The bitterness of peptides was reduced in LMPC-T-F_G compared with LMPC-T-F. The potential application of the E-tongue using a standard model solution with quinine was shown to follow the bitterness of peptides. Full article

(This article belongs to the Special Issue Bioinspired Chemical Sensors and Micro-Nano Devices)

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13 pages, 1970 KiB

Open AccessArticle

Screen-Printed Gold Electrode Functionalized with Deferoxamine for Iron(III) Detection

by Giancarla Alberti, Camilla Zanoni, Sara Rovertoni, Lisa Rita Magnaghi and Raffaela Biesuz

Chemosensors 2022, 10(6), 214; https://doi.org/10.3390/chemosensors10060214 - 6 Jun 2022

Cited by 11 | Viewed by 2962

Abstract

Deferoxamine (DFO), a hydroxamic siderophore with a high affinity for Fe(III), is immobilized as a functionalized self-assembled monolayer of a thiol (SAM) on the gold surface of a screen-printed cell to develop a voltammetric sensor for iron(III). The surface of the working electrode [...] Read more.

Deferoxamine (DFO), a hydroxamic siderophore with a high affinity for Fe(III), is immobilized as a functionalized self-assembled monolayer of a thiol (SAM) on the gold surface of a screen-printed cell to develop a voltammetric sensor for iron(III). The surface of the working electrode was characterized, before and after functionalization, by determining surface properties such as the area and the double-layer capacitance. The Fe(III) detection was performed by DPV analysis after preconcentration of the cation at the open circuit potential in solution at pH = 1 for two minutes. The method was applied to the iron(III) quantification in water samples giving promising results. Full article

(This article belongs to the Section Electrochemical Devices and Sensors)

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15 pages, 7462 KiB

Open AccessArticle

Nitrogen Dioxide Optical Sensor Based on Redox-Active Tetrazolium/Pluronic Nanoparticles Embedded in PDMS Membranes

by Esteban Araya-Hermosilla, Rodrigo Araya-Hermosilla, Francesco Visentin, Francesco Picchioni, Andrea Pucci and Virgilio Mattoli

Chemosensors 2022, 10(6), 213; https://doi.org/10.3390/chemosensors10060213 - 6 Jun 2022

Cited by 1 | Viewed by 2247

Abstract

Anthropogenic toxic vapour and gases are a worldwide threat for human health and to the environment. Therefore, it is crucial to develop highly sensitive devices that guarantee their rapid detection. Here, we prepared redox-switchable colloids by the in-situ reduction of 2,3,5-triphenyl-2H-tetrazolium (TTC) into [...] Read more.

Anthropogenic toxic vapour and gases are a worldwide threat for human health and to the environment. Therefore, it is crucial to develop highly sensitive devices that guarantee their rapid detection. Here, we prepared redox-switchable colloids by the in-situ reduction of 2,3,5-triphenyl-2H-tetrazolium (TTC) into triphenyl formazan (TF) stabilised with Pluronic F127 in aqueous media. The colloids were readily embedded in polydimethylsiloxane (PDMS) to produce a selective colour-switchable membrane for nitrogen dioxide (NO₂) detection. We found that the TTC reduction resulted in the production of red-coloured colloids with zeta potential between −1 to 3 mV and hydrodynamic diameters between 114 to 305 nm as hydrophobic dispersion in aqueous media stabilised by Pluronic at different molar concentrations. Moreover, the embedded colloids rendered highly homogenous red colour gas-permeable PDMS elastomeric membrane. Once exposed to NO₂, the membrane began to bleach after 30 s due to the oxidation of the embedded TF and undergo a complete decolouration after 180 s. Such features allowed the membrane integration in a low-cost sensing device that showed a high sensitivity and low detection limit to NO₂. Full article

(This article belongs to the Special Issue Feature Papers on Optical Chemical Sensors and Biosensors)

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10 pages, 2347 KiB

Open AccessCommunication

Gas-Sensing Properties of Dissolved Gases in Insulating Material Adsorbed on SnO₂–GeSe Monolayer

by Liang-Yan Guo, Suning Liang, Zhi Yang, Lingfeng Jin, Yaxiong Tan and Zhengyong Huang

Chemosensors 2022, 10(6), 212; https://doi.org/10.3390/chemosensors10060212 - 5 Jun 2022

Cited by 8 | Viewed by 2345

Abstract

In a transformer, the insulation materials will produce different dissolved gases due to various faults in the operation of the transformer, in which C₂H₂, CH₄, and H₂ are the main dissolved gases. In this study, the [...] Read more.

In a transformer, the insulation materials will produce different dissolved gases due to various faults in the operation of the transformer, in which C₂H₂, CH₄, and H₂ are the main dissolved gases. In this study, the adsorption characteristics of the above three gases on the SnO₂–GeSe monolayer surface were discussed and analyzed based on the density functional theory. The adsorption energy, transfer charge, geometric structure parameters, electronic density of states, electronic local function, charge difference density, and recovery time were calculated and compared to characterize the gas-sensing adsorption mechanism. The results showed that the SnO₂–GeSe monolayer exhibited good adsorption capacity, selectivity, and repeatability for the three characteristic dissolved gases. After adsorbing CH₄ gas molecules, the conductivity of the SnO₂–GeSe monolayer decreased. After adsorbing C₂H₂ and H₂ gas molecules, the conductivity of the SnO₂–GeSe monolayer increased. Therefore, the SnO₂–GeSe monolayer has great application potential in the real-time monitoring of dissolved gases in insulating materials, which may become a new type of resistive gas sensor. Full article

(This article belongs to the Section Nanostructures for Chemical Sensing)

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13 pages, 3627 KiB

Open AccessArticle

Preparation of Au@ZnO Nanofilms by Combining Magnetron Sputtering and Post-Annealing for Selective Detection of Isopropanol

by Guodong Wang, Pengju Wu, Lanlan Guo, Wei Wang, Wenqiang Liu, Yuanyuan Wang, Tingyu Chen, Haohan Wang, Yonghao Xu and Yingli Yang

Chemosensors 2022, 10(6), 211; https://doi.org/10.3390/chemosensors10060211 - 3 Jun 2022

Cited by 12 | Viewed by 2157

Abstract

We demonstrate the highly sensitive and fast response/recovery gas sensors for detecting isopropanol (IPA), in which the Au-nanoparticles-modified ZnO (Au@ZnO) nanofilms act as the active layers. The data confirm that both the response and the response/recovery speed for the detection of IPA are [...] Read more.

We demonstrate the highly sensitive and fast response/recovery gas sensors for detecting isopropanol (IPA), in which the Au-nanoparticles-modified ZnO (Au@ZnO) nanofilms act as the active layers. The data confirm that both the response and the response/recovery speed for the detection of IPA are significantly improved by adding Au nanoparticles on the surface of ZnO nanofilms. The gas sensor with an Optimum Au@ZnO nanofilm exhibits the highest responses of 160 and 7 to the 100 and 1 ppm IPA at 300 °C, which indicates high sensitivity and a very low detecting limit. The sensor also exhibits a very short response/recovery time of 4/15 s on the optimized Au@ZnO nanofilm, which is much shorter than that of the sensor with a pure ZnO nanofilm. The mechanisms of the performance improvement in the sensors are discussed in detail. Both the electronic sensitization and the chemical sensitization of the ZnO nanofilms are improved by the modified Au nanoparticles, which not only regulate the thickness of the depletion layer but also increase the amount of adsorbed oxygen species on the surfaces. This work proposes a strategy to develop a highly sensitive gas sensor for real-time monitoring of IPA. Full article

(This article belongs to the Special Issue High-Sensitivity and -Selectivity Gas Sensors with Nanoparticles, Nanostructures, and Thin Films)

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13 pages, 2643 KiB

Open AccessArticle

Isothermal Amplification and Lateral Flow Nucleic Acid Test for the Detection of Shiga Toxin-Producing Bacteria for Food Monitoring

by Sabrina Petrucci, Emre Dikici, Sylvia Daunert and Sapna K. Deo

Chemosensors 2022, 10(6), 210; https://doi.org/10.3390/chemosensors10060210 - 2 Jun 2022

Cited by 5 | Viewed by 2573

Abstract

Foodborne bacteria have persisted as a significant threat to public health and to the food and agriculture industry. Due to the widespread impact of these pathogens, there has been a push for the development of strategies that can rapidly detect foodborne bacteria on-site. [...] Read more.

Foodborne bacteria have persisted as a significant threat to public health and to the food and agriculture industry. Due to the widespread impact of these pathogens, there has been a push for the development of strategies that can rapidly detect foodborne bacteria on-site. Shiga toxin-producing E. coli strains (such as E. coli O157:H7, E. coli O121, and E. coli O26) from contaminated food have been a major concern. They carry genes stx1 and/or stx2 that produce two toxins, Shiga toxin 1 and Shiga toxin 2, which are virulent proteins. In this work, we demonstrate the development of a rapid test based on an isothermal recombinase polymerase amplification reaction for two Shiga toxin genes in a single reaction. Results of the amplification reaction are visualized simultaneously for both Shiga toxins on a single lateral flow paper strip. This strategy targets the DNA encoding Shiga toxin 1 and 2, allowing for broad detection of any Shiga toxin-producing bacterial species. From sample to answer, this method can achieve results in approximately 35 min with a detection limit of 10 CFU/mL. This strategy is sensitive and selective, detecting only Shiga toxin-producing bacteria. There was no interference observed from non-pathogenic or pathogenic non-Shiga toxin-producing bacteria. A detection limit of 10 CFU/mL for Shiga toxin-producing E. coli was also obtained in a food matrix. This strategy is advantageous as it allows for timely identification of Shiga toxin-related contamination for quick initial food contamination assessments. Full article

(This article belongs to the Special Issue State of the Art in Nucleic Acid Detection)

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13 pages, 2346 KiB

Open AccessArticle

A Highly Sensitive Electrochemical Sensor for Cd²⁺ Detection Based on Prussian Blue-PEDOT-Loaded Laser-Scribed Graphene-Modified Glassy Carbon Electrode

by Londhe Akash Machhindra and Yi-Kuang Yen

Chemosensors 2022, 10(6), 209; https://doi.org/10.3390/chemosensors10060209 - 2 Jun 2022

Cited by 20 | Viewed by 3731

Abstract

Heavy metal ion pollution has had a serious influence on human health and the environment. Therefore, the monitoring of heavy metal ions is of great practical significance. In this work, we describe the development of an electrochemical sensor to detect cadmium (Cd²⁺ [...] Read more.

Heavy metal ion pollution has had a serious influence on human health and the environment. Therefore, the monitoring of heavy metal ions is of great practical significance. In this work, we describe the development of an electrochemical sensor to detect cadmium (Cd²⁺) using a Prussian blue (PB), poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT)-loaded laser-scribed graphene (LSG) nanocomposite-modified glassy carbon electrode (GCE). In this nanocomposite material, we successfully brought together the advantages of an extraordinarily large surface area. The accumulation of PB nanoparticles results in an efficient electrochemical sensor with high sensitivity and selectivity and fast detection ability, developed for the trace-level detection of Cd²⁺. Electrochemical features were explored via cyclic voltammetry (CV), whereas the stripping voltammetry behavior of modified electrodes was analyzed by utilizing differential pulse voltammetry. Compared with bare GCE, the LSG/PB-PEDOT/GCE modified electrode greatly increased the anodic stripping peak currents of Cd²⁺. Under the optimized conditions, the direct and facile detection of Cd²⁺ was achieved with a wide linear range (1 nM–10 µM) and a low LOD (0.85 nM). Full article

(This article belongs to the Special Issue Selected Papers from the International conference on Smart Sensors (ICSS 2021))

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11 pages, 1357 KiB

Open AccessArticle

A Taste Bud Organoid-Based Microelectrode Array Biosensor for Taste Sensing

by Shuge Liu, Ping Zhu, Yulan Tian, Yating Chen, Yage Liu, Miaomiao Wang, Wei Chen, Liping Du and Chunsheng Wu

Chemosensors 2022, 10(6), 208; https://doi.org/10.3390/chemosensors10060208 - 2 Jun 2022

Cited by 7 | Viewed by 3219

Abstract

The biological taste system has the unique ability to detect taste substances. Biomaterials originating from a biological taste system have been recognized as ideal candidates to serve as sensitive elements in the development of taste-based biosensors. In this study, we developed a taste [...] Read more.

The biological taste system has the unique ability to detect taste substances. Biomaterials originating from a biological taste system have been recognized as ideal candidates to serve as sensitive elements in the development of taste-based biosensors. In this study, we developed a taste bud organoid-based biosensor for the research of taste sensation. Taste bud organoids prepared from newborn mice were cultured and loaded onto the surface of a 64-channel microelectrode array (MEA) chip to explore the electrophysiological changes upon taste; an MEA chip was used to simultaneously record multiple-neuron firing activities from taste bud organoids under different taste stimuli, which helped to reveal the role of taste buds in taste sensing. The obtained results show that taste cells separated from the taste epithelium grew well into spherical structures under 3D culture conditions. These structures were composed of multiple cells with obvious budding structures. Moreover, the multicellular spheres were seeded on a 64-channel microelectrode array and processed with different taste stimuli. It was indicated that the MEA chip could efficiently monitor the electrophysiological signals from taste bud organoids in response to various taste stimuli. This biosensor provides a new method for the study of taste sensations and taste bud functions. Full article

(This article belongs to the Special Issue Bioinspired Chemical Sensors and Micro-Nano Devices)

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12 pages, 3692 KiB

Open AccessCommunication

A Ratiometric Selective Fluorescent Probe Derived from Pyrene for Cu²⁺ Detection

by Chunwei Yu, Mei Yang, Shuhua Cui, Yuxiang Ji and Jun Zhang

Chemosensors 2022, 10(6), 207; https://doi.org/10.3390/chemosensors10060207 - 31 May 2022

Cited by 5 | Viewed by 2569

Abstract

A novel ratiometric Cu²⁺-selective probe was rationally constructed based on pyrene derivative. Compared to other tested metal ions, the probe presented the selective recognition for Cu²⁺ which could be detected by a significant turn-on fluorescent response at 393 nm and [...] Read more.

A novel ratiometric Cu²⁺-selective probe was rationally constructed based on pyrene derivative. Compared to other tested metal ions, the probe presented the selective recognition for Cu²⁺ which could be detected by a significant turn-on fluorescent response at 393 nm and 415 nm. Under the optimized conditions, a detection limit of 0.16 μM Cu²⁺ in aqueous media was found. Besides this, a 1:1 metal–ligand complex was confirmed by MS spectra and Job’s plot experiment, and the binding mode was also studied by ¹H NMR experiment. Meanwhile, the fluorescence imaging in living cells was performed to detect Cu²⁺ with satisfactory results. Full article

(This article belongs to the Special Issue Fluorescent Sensors for Disease Diagnosis and Therapy)

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23 pages, 4919 KiB

Open AccessReview

Recent Progresses in NIR-II Luminescent Bio/Chemo Sensors Based on Lanthanide Nanocrystals

by Tingyu Yang, Jinglei Qin, Jinling Zhang, Lanying Guo, Mu Yang, Xi Wu, Mei You and Hongshang Peng

Chemosensors 2022, 10(6), 206; https://doi.org/10.3390/chemosensors10060206 - 30 May 2022

Cited by 8 | Viewed by 2773

Abstract

Fluorescent bio/chemosensors are widely used in the field of biological research and medical diagnosis, with the advantages of non-invasiveness, high sensitivity, and good selectivity. In particular, luminescent bio/chemosensors, based on lanthanide nanocrystals (LnNCs) with a second near-infrared (NIR-II) emission, have attracted much attention, [...] Read more.

Fluorescent bio/chemosensors are widely used in the field of biological research and medical diagnosis, with the advantages of non-invasiveness, high sensitivity, and good selectivity. In particular, luminescent bio/chemosensors, based on lanthanide nanocrystals (LnNCs) with a second near-infrared (NIR-II) emission, have attracted much attention, owing to greater penetration depth, aside from the merits of narrow emission band, abundant emission lines, and long lifetimes. In this review, NIR-II LnNCs-based bio/chemo sensors are summarized from the perspectives of the mechanisms of NIR-II luminescence, synthesis method of LnNCs, strategy of luminescence enhancement, sensing mechanism, and targeted bio/chemo category. Finally, the problems that exist in present LnNCs-based bio/chemosensors are discussed, and the future development trend is prospected. Full article

(This article belongs to the Special Issue Chemical and Biosensors: A Theme Issue in Honor of Professor Otto S. Wolfbeis)

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13 pages, 2470 KiB

Open AccessCommunication

Investigating Organic Vapor Sensing Properties of Composite Carbon Nanotube-Zinc Oxide Nanowire

by Mostafa Shooshtari, Saeideh Pahlavan, Saeideh Rahbarpour and Hasan Ghafoorifard

Chemosensors 2022, 10(6), 205; https://doi.org/10.3390/chemosensors10060205 - 29 May 2022

Cited by 10 | Viewed by 2515

Abstract

The low operating temperature of nanowire gas sensors along with their high surface-to-volume ratio are two factors that make gas sensors more practical. In this paper, the growth of ZnO nanowires on a vertically aligned CNT forest is reported. The utilized method for [...] Read more.

The low operating temperature of nanowire gas sensors along with their high surface-to-volume ratio are two factors that make gas sensors more practical. In this paper, the growth of ZnO nanowires on a vertically aligned CNT forest is reported. The utilized method for ZnO growth was a rapid microwave-assisted hydrothermal route, which facilitates low-temperature and ultra-fast fabrication. Organic vapor sensing properties of fabricated samples were studied in response to different alcoholic vapors at a wide operating temperature range of 25 to 300 °C. Enhancement of the gas response was observed with increasing operating temperature. Moreover, the effect of the ZnO nanowire length on organic vapor sensing properties of CNT-ZnO samples was investigated. Results proved that CNT-ZnO samples with long ZnO wires exhibit higher sensitivity to examined analytes. Different length ZnO nanowires were attained via variation of the microwave exposure time and power. Fabrication parameters were selected based on numerous runs. The length of ZnO synthesized at each distinct run was calculated based on SEM micrographs of the samples. Full article

(This article belongs to the Topic Synthesis and Applications of Nanostructured Metals and Metal Oxides)

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17 pages, 2194 KiB

Open AccessArticle

The Usefulness of Autoradiography for DNA Repair Proteins Activity Detection in the Cytoplasm towards Radiolabeled Oligonucleotides Containing 5′,8-Cyclo-2′-deoxyadenosine

by Karolina Boguszewska, Bolesław T. Karwowski and Julia Kaźmierczak-Barańska

Chemosensors 2022, 10(6), 204; https://doi.org/10.3390/chemosensors10060204 - 28 May 2022

Viewed by 2364

Abstract

Autoradiography of ³²P-radiolabeled oligonucleotides is one of the most precise detection methods of DNA repair processes. In this study, autoradiography allowed assessing the activity of proteins in the cytoplasm involved in DNA repair. The cytoplasm is the site of protein biosynthesis but [...] Read more.

Autoradiography of ³²P-radiolabeled oligonucleotides is one of the most precise detection methods of DNA repair processes. In this study, autoradiography allowed assessing the activity of proteins in the cytoplasm involved in DNA repair. The cytoplasm is the site of protein biosynthesis but is also a target cellular compartment of synthetic therapeutic oligonucleotide (STO) delivery. The DNA-based drugs may be impaired by radiation-induced lesions, such as clustered DNA lesions (CDL) and/or 5′,8-cyclo-2′-deoxypurines (cdPu). CDL and cdPu may appear in the sequence of STO after irradiation and subsequently impair DNA repair, as shown in previous studies. Hence, the interesting questions are (1) is it safe to combine STO treatment with radiotherapy; (2) are repair proteins active in the cytoplasm; and (3) is their activity different in the cytoplasm than in the nucleus? This unique study examined whether the proteins involved in the DNA repair are affected by the CDL while they are still present in the cytoplasm of xrs5, BJ, and XPC cells. Double-stranded oligonucleotides with bi-stranded CDL were used (containing AP site in one strand and a (5′S) or (5′R) 5′,8-cyclo-2′-deoxyadenosine (cdA) in the other strand located 1 or 4 bp in both directions). The results have shown that the proteins involved in the repair were active in the cytoplasm, but less than in the nucleus. The general trends aligned for cytoplasm and nucleus—lesions located in the 5′-end direction inhibited the course of DNA repair. The combination of STO with radiotherapy should be applied carefully, as unrepaired lesions within STO may impair their therapeutic efficiency. Full article

(This article belongs to the Special Issue State of the Art in Nucleic Acid Detection)

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