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Advanced Field-Effect Sensors

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

Deadline for manuscript submissions: closed (31 December 2022) | Viewed by 35807

Special Issue Editor

Department of Physics “E.R. Caianiello”, University of Salerno, 84084 Fisciano, Italy
Interests: optical and electrical properties of nanostructured materials such as carbon nanotubes, graphene, and 2D materials; van der Waals heterostructures and Schottky junctions; field-effect transistors; non-volatile memories; solar cells; photodetectors; field emission devices
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Special Issue Information

Dear Colleagues,

Sensor devices based on the field-effect principle have been used for more than fifty years in a variety of applications ranging from bio-chemical sensing to radiation detection or environmental parameters monitoring. The basic working principle of field-effect sensors is the same as that of field-effect transistors (FETs), in which the conductance between two electrodes (source and drain) is controlled by the electric field generated by a gate.

Field-effect biochemical sensors have found increasing applications for pH and molecular or DNA sensing since the proposal of the ion-sensitive field-effect transistor (ISFET) by Bergerveld in 1968.

Field-effect devices have been extensively exploited for gas and pressure sensing. Photo-FETs are popular light intensity sensors. FETs, both the junction (JFET) and metal-oxide-semiconductor (MOSFET) type, are widely used as photodetectors and ionizing radiation detectors or dosimeters in radioprotection, radiotherapy, medicine, and dentistry.

FETs enable sensitive temperature sensors and piezoelectric strain gauges.

The advent of nanostructured materials in the past three decades has created opportunities to integrate new sensing materials or develop innovative architectures in field-effect-based sensors. The optimization of existing devices, research on new field-effect structures and fabrication techniques, and the design of novel electronic systems for signal amplification and processing are currently underway.

A great advantage of field-effect sensors is that they provide intrinsic signal amplification and can be integrated with the electronics needed for the sensor signal processing on the same semiconductor chip. Moreover, field-effect sensors feature high sensitivity, low-cost, and miniaturization.

Field-effect based sensing offers several challenges stemming from the highly interdisciplinary nature of the problems encountered, in which knowledge of material science, surface chemistry and physics, biomolecular kinetics, electronic engineering, etc. are required.

This Special Issue will present recent progress in the fabrication, design, understanding, and utilization of field-effect sensors for any applications.

The Special Issues will collect research papers reporting novel experimental, theoretical, or simulation results dealing with field-effect sensors. Review articles that offer comprehensive coverage of specific aspects or new insights and perspectives are welcome.

Prof. Dr. Antonio Bartolomeo
Guest Editor

Manuscript Submission Information

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Keywords

  • Potentiometric sensors
  • Floating gate, extended-gate, and dual-gate FET sensors
  • Bio-chemical sensors
  • pH sensing
  • ISFET, EISFET, affinity-based FET
  • Chemical field-effect transistor, ChemFET
  • Biomolecular sensing, BioFET
  • DNA FET
  • Immunologically modified FET, IMFET
  • Gas sensors, gasFET
  • Photodetectors, Photo-FET
  • Radiation sensitive FETs, RADFET
  • FET dosimeters
  • Pressure field-effect sensors
  • Temperature field-effect sensors
  • Field-effect strain sensors
  • Nanomaterials in field-effect sensors
  • Nanowire field-effect sensors
  • 2D-material field-effect sensors
  • Graphene field-effect sensors
  • Signal amplification
  • Sensor signal processing

Published Papers (15 papers)

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Editorial

Jump to: Research, Review

5 pages, 209 KiB  
Editorial
Advanced Field-Effect Sensors
by Antonio Di Bartolomeo
Sensors 2023, 23(9), 4554; https://0-doi-org.brum.beds.ac.uk/10.3390/s23094554 - 08 May 2023
Cited by 1 | Viewed by 1283
Abstract
Sensors based on the field-effect principle have been used for more than fifty years in a variety of applications ranging from bio-chemical sensing to radiation detection or environmental parameter monitoring [...] Full article
(This article belongs to the Special Issue Advanced Field-Effect Sensors)

Research

Jump to: Editorial, Review

16 pages, 4347 KiB  
Article
Compact Modeling of Two-Dimensional Field-Effect Biosensors
by Francisco Pasadas, Tarek El Grour, Enrique G. Marin, Alberto Medina-Rull, Alejandro Toral-Lopez, Juan Cuesta-Lopez, Francisco G. Ruiz, Lassaad El Mir and Andrés Godoy
Sensors 2023, 23(4), 1840; https://0-doi-org.brum.beds.ac.uk/10.3390/s23041840 - 07 Feb 2023
Cited by 3 | Viewed by 1692
Abstract
A compact model able to predict the electrical read-out of field-effect biosensors based on two-dimensional (2D) semiconductors is introduced. It comprises the analytical description of the electrostatics including the charge density in the 2D semiconductor, the site-binding modeling of the barrier oxide surface [...] Read more.
A compact model able to predict the electrical read-out of field-effect biosensors based on two-dimensional (2D) semiconductors is introduced. It comprises the analytical description of the electrostatics including the charge density in the 2D semiconductor, the site-binding modeling of the barrier oxide surface charge, and the Stern layer plus an ion-permeable membrane, all coupled with the carrier transport inside the biosensor and solved by making use of the Donnan potential inside the ion-permeable membrane formed by charged macromolecules. This electrostatics and transport description account for the main surface-related physical and chemical processes that impact the biosensor electrical performance, including the transport along the low-dimensional channel in the diffusive regime, electrolyte screening, and the impact of biological charges. The model is implemented in Verilog-A and can be employed on standard circuit design tools. The theoretical predictions obtained with the model are validated against measurements of a MoS2 field-effect biosensor for streptavidin detection showing excellent agreement in all operation regimes and leading the way for the circuit-level simulation of biosensors based on 2D semiconductors. Full article
(This article belongs to the Special Issue Advanced Field-Effect Sensors)
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23 pages, 5722 KiB  
Article
Design of Pyrrole-Based Gate-Controlled Molecular Junctions Optimized for Single-Molecule Aflatoxin B1 Detection
by Fabrizio Mo, Chiara Elfi Spano, Yuri Ardesi, Massimo Ruo Roch, Gianluca Piccinini and Mariagrazia Graziano
Sensors 2023, 23(3), 1687; https://0-doi-org.brum.beds.ac.uk/10.3390/s23031687 - 03 Feb 2023
Cited by 2 | Viewed by 1775
Abstract
Food contamination by aflatoxins is an urgent global issue due to its high level of toxicity and the difficulties in limiting the diffusion. Unfortunately, current detection techniques, which mainly use biosensing, prevent the pervasive monitoring of aflatoxins throughout the agri-food chain. In this [...] Read more.
Food contamination by aflatoxins is an urgent global issue due to its high level of toxicity and the difficulties in limiting the diffusion. Unfortunately, current detection techniques, which mainly use biosensing, prevent the pervasive monitoring of aflatoxins throughout the agri-food chain. In this work, we investigate, through ab initio atomistic calculations, a pyrrole-based Molecular Field Effect Transistor (MolFET) as a single-molecule sensor for the amperometric detection of aflatoxins. In particular, we theoretically explain the gate-tuned current modulation from a chemical–physical perspective, and we support our insights through simulations. In addition, this work demonstrates that, for the case under consideration, the use of a suitable gate voltage permits a considerable enhancement in the sensor performance. The gating effect raises the current modulation due to aflatoxin from 100% to more than 103÷104%. In particular, the current is diminished by two orders of magnitude from the μA range to the nA range due to the presence of aflatoxin B1. Our work motivates future research efforts in miniaturized FET electrical detection for future pervasive electrical measurement of aflatoxins. Full article
(This article belongs to the Special Issue Advanced Field-Effect Sensors)
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14 pages, 9221 KiB  
Article
CMOS Detector Staggered Array Module for Sub-Terahertz Imaging on Conveyor Belt System
by Moon-Jeong Lee, Ha-Neul Lee, Ga-Eun Lee, Seong-Tae Han, Dong-Woo Kang and Jong-Ryul Yang
Sensors 2023, 23(3), 1232; https://0-doi-org.brum.beds.ac.uk/10.3390/s23031232 - 20 Jan 2023
Cited by 1 | Viewed by 1595
Abstract
A complementary metal–oxide–semiconductor (CMOS) detector array is proposed to improve the sub-terahertz imaging resolution for objects in the conveyor belt system. The image resolution is limited to the implemented configuration, such as the wide spacing in the detector array, the high conveyor belt [...] Read more.
A complementary metal–oxide–semiconductor (CMOS) detector array is proposed to improve the sub-terahertz imaging resolution for objects in the conveyor belt system. The image resolution is limited to the implemented configuration, such as the wide spacing in the detector array, the high conveyor belt speed, and the slow response of the signal conditioning block. The proposed array can improve the image resolution in the direction perpendicular to the movement of the belt, which is determined by the size and interval of the detector pixel, by configuring the array into two replaceable columns located at the misaligned horizontal positions. Replaceable detector unit pixels are individually attached to the motherboard after measuring and evaluating the detection performance to construct the proposed array. The intensities of 32 detector pixels placed under the conveyor belt with a width of 160 mm were initially calibrated in every image, including the beam pattern of 0.2 THz signals generated from the gyrotron. The image resolution of the perpendicular direction obtained from the proposed array was measured to be approximately 5 mm at a conveyor belt speed of 16 mm/s, demonstrating a 200% improvement in resolution compared to the conventional linear array under the same conditions. Full article
(This article belongs to the Special Issue Advanced Field-Effect Sensors)
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12 pages, 4518 KiB  
Article
Combination of Material Processing and Characterization Methods for Miniaturization of Field-Effect Gas Sensor
by Nikolay Samotaev, Artur Litvinov, Konstantin Oblov, Maya Etrekova, Boris Podlepetsky and Pavel Dzhumaev
Sensors 2023, 23(1), 514; https://0-doi-org.brum.beds.ac.uk/10.3390/s23010514 - 03 Jan 2023
Cited by 4 | Viewed by 1254
Abstract
The technological approach for the low-scale production of field-effect gas sensors as electronic components for use in non-lab ambient environments is described. In this work, in addition to the mechanical protection of a gas-sensitive structure, an emphasis was also placed on the very [...] Read more.
The technological approach for the low-scale production of field-effect gas sensors as electronic components for use in non-lab ambient environments is described. In this work, in addition to the mechanical protection of a gas-sensitive structure, an emphasis was also placed on the very topical issue of thermal stabilization around the one temperature point, even if it is several degrees higher than the surrounding one, which will probably also be useful for any type of application for many types of field-effect sensors. Considerable attention was paid to the characterization of the results obtained by various invasive and non-invasive methods for diagnosing the manufactured construction. The technology described in this article occupies an intermediate position between laboratory samples tested in clean rooms with stable ambient atmospheres, and experimental and small-scale production sensors designed for real operating conditions to solve the narrow application of measuring low concentrations of hydrogen. Full article
(This article belongs to the Special Issue Advanced Field-Effect Sensors)
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14 pages, 3912 KiB  
Article
A Virtual Electronic Nose for the Efficient Classification and Quantification of Volatile Organic Compounds
by Guillem Domènech-Gil and Donatella Puglisi
Sensors 2022, 22(19), 7340; https://0-doi-org.brum.beds.ac.uk/10.3390/s22197340 - 27 Sep 2022
Cited by 3 | Viewed by 2291
Abstract
Although many chemical gas sensors report high sensitivity towards volatile organic compounds (VOCs), finding selective gas sensing technologies that can classify different VOCs is an ongoing and highly important challenge. By exploiting the synergy between virtual electronic noses and machine learning techniques, we [...] Read more.
Although many chemical gas sensors report high sensitivity towards volatile organic compounds (VOCs), finding selective gas sensing technologies that can classify different VOCs is an ongoing and highly important challenge. By exploiting the synergy between virtual electronic noses and machine learning techniques, we demonstrate the possibility of efficiently discriminating, classifying, and quantifying short-chain oxygenated VOCs in the parts-per-billion concentration range. Several experimental results show a reproducible correlation between the predicted and measured values. A 10-fold cross-validated quadratic support vector machine classifier reports a validation accuracy of 91% for the different gases and concentrations studied. Additionally, a 10-fold cross-validated partial least square regression quantifier can predict their concentrations with coefficients of determination, R2, up to 0.99. Our methodology and analysis provide an alternative approach to overcoming the issue of gas sensors’ selectivity, and have the potential to be applied across various areas of science and engineering where it is important to measure gases with high accuracy. Full article
(This article belongs to the Special Issue Advanced Field-Effect Sensors)
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8 pages, 2570 KiB  
Communication
Opto Field-Effect Transistors for Detecting Quercetin–Cu2+ Complex
by Pradhana Jati Budhi Laksana, Li-Chu Tsai, Chang-Cheng Lin, Kuei-Shu Chang-Liao, Mathew K. Moodley and Chii-Dong Chen
Sensors 2022, 22(19), 7219; https://0-doi-org.brum.beds.ac.uk/10.3390/s22197219 - 23 Sep 2022
Cited by 1 | Viewed by 1662
Abstract
In this study, we explored the potential of applying biosensors based on silicon nanowire field-effect transistors (bio–NWFETs) as molecular absorption sensors. Using quercetin and Copper (Cu2+) ion as an example, we demonstrated the use of an opto–FET approach for the detection [...] Read more.
In this study, we explored the potential of applying biosensors based on silicon nanowire field-effect transistors (bio–NWFETs) as molecular absorption sensors. Using quercetin and Copper (Cu2+) ion as an example, we demonstrated the use of an opto–FET approach for the detection of molecular interactions. We found that photons with wavelengths of 450 nm were absorbed by the molecular complex, with the absorbance level depending on the Cu2+ concentration. Quantitative detection of the molecular absorption of metal complexes was performed for Cu2+ concentrations ranging between 0.1 μM and 100 μM, in which the photon response increased linearly with the copper concentration under optimized bias parameters. Our opto–FET approach showed an improved absorbance compared with that of a commercial ultraviolet-visible spectrophotometry. Full article
(This article belongs to the Special Issue Advanced Field-Effect Sensors)
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10 pages, 2510 KiB  
Communication
A Multimodal Sensing Device for Simultaneous Measurement of Dissolved Oxygen and Hydrogen Ions by Monolithic Integration of FET-Based Sensors
by Toshihiko Noda, Sylvia Mei Lin Loo, Yoshiko Noda, Daisuke Akai, Takeshi Hizawa, Yong-Joon Choi, Kazuhiro Takahashi and Kazuaki Sawada
Sensors 2022, 22(17), 6669; https://0-doi-org.brum.beds.ac.uk/10.3390/s22176669 - 03 Sep 2022
Cited by 3 | Viewed by 2080
Abstract
We examined the possibility of measuring dissolved oxygen by using a potentiometric solid-state semiconductor sensor. Thin films of tin (IV) oxide (SnO2) are widely used in oxygen gas sensors. However, their ability to detect dissolved oxygen (DO) in solutions is still [...] Read more.
We examined the possibility of measuring dissolved oxygen by using a potentiometric solid-state semiconductor sensor. Thin films of tin (IV) oxide (SnO2) are widely used in oxygen gas sensors. However, their ability to detect dissolved oxygen (DO) in solutions is still unknown. In this paper, we present a method for investigating the dissolved oxygen-sensing properties of SnO2 thin films in solutions by fabricating a SnO2-gate field-effect transistor (FET). A similarly structured hydrogen ion-sensitive silicon nitride (Si3N4)-gate FET was fabricated using the same method. The transfer characteristics and sensitivities were experimentally obtained and compared. The transfer characteristics of the FET show a shift in threshold voltage in response to a decrease in DO concentration. The SnO2-gate FET exhibited a sensitivity of 4 mV/ppm, whereas the Si3N4-gate FET showed no response to DO. Although the SnO2-gate FET responds to pH changes in the solution, this sensitivity issue can be eliminated by using a Si3N4-gate FET, which is capable of selectively sensing hydrogen ions without DO sensitivity. The experimental results indicate the promising properties of SnO2 thin films for multimodal sensing applications. Full article
(This article belongs to the Special Issue Advanced Field-Effect Sensors)
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15 pages, 6527 KiB  
Article
The Characteristics Analysis of a Microfluid-Based EGFET Biosensor with On-Chip Sensing Film for Lactic Acid Detection
by Po-Yu Kuo, Chun-Hung Chang, Wei-Hao Lai and Tai-Hui Wang
Sensors 2022, 22(15), 5905; https://0-doi-org.brum.beds.ac.uk/10.3390/s22155905 - 07 Aug 2022
Cited by 4 | Viewed by 2478
Abstract
In this research, a microfluid-based extended gate field-effect transistor (EGFET) biosensor with an on-chip sensing window (OCSW) was fabricated. The detection window was composed of six metal layers, and a ruthenium dioxide (RuO2) film was spattered on the surface and functionalized [...] Read more.
In this research, a microfluid-based extended gate field-effect transistor (EGFET) biosensor with an on-chip sensing window (OCSW) was fabricated. The detection window was composed of six metal layers, and a ruthenium dioxide (RuO2) film was spattered on the surface and functionalized with lactase to detect lactic acid (LA). To detect LA in a more diversified way, a microfluidic system was integrated with the biosensor. Moreover, a special package was used to seal the sensing window and microfluidic tube and insulate it from other parts to prevent water molecule invasion and chip damage. The sensitivity analysis of the EGFET biosensor was studied by a semiconductor parameter analyzer (SPA). The static and dynamic measurements of the EGFET with sensing windows on a chip were analyzed. The sensing characteristics of the EGFET biosensor were verified by the experimental results. The proposed biosensor is suitable for wearable applications due to the advantages of its low weight, low voltage, and simple manufacturing process. Full article
(This article belongs to the Special Issue Advanced Field-Effect Sensors)
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23 pages, 6146 KiB  
Article
Electronic Sensing Platform (ESP) Based on Open-Gate Junction Field-Effect Transistor (OG-JFET) for Life Science Applications: Design, Modeling and Experimental Results
by Abbas Panahi, Deniz Sadighbayan and Ebrahim Ghafar-Zadeh
Sensors 2021, 21(22), 7491; https://0-doi-org.brum.beds.ac.uk/10.3390/s21227491 - 11 Nov 2021
Cited by 5 | Viewed by 2651
Abstract
This paper presents a new field-effect sensor called open-gate junction gate field-effect transistor (OG-JFET) for biosensing applications. The OG-JFET consists of a p-type channel on top of an n-type layer in which the p-type serves as the sensing conductive layer between two ohmic [...] Read more.
This paper presents a new field-effect sensor called open-gate junction gate field-effect transistor (OG-JFET) for biosensing applications. The OG-JFET consists of a p-type channel on top of an n-type layer in which the p-type serves as the sensing conductive layer between two ohmic contacted sources and drain electrodes. The structure is novel as it is based on a junction field-effect transistor with a subtle difference in that the top gate (n-type contact) has been removed to open the space for introducing the biomaterial and solution. The channel can be controlled through a back gate, enabling the sensor’s operation without a bulky electrode inside the solution. In this research, in order to demonstrate the sensor’s functionality for chemical and biosensing, we tested OG-JFET with varying pH solutions, cell adhesion (human oral neutrophils), human exhalation, and DNA molecules. Moreover, the sensor was simulated with COMSOL Multiphysics to gain insight into the sensor operation and its ion-sensitive capability. The complete simulation procedures and the physics of pH modeling is presented here, being numerically solved in COMSOL Multiphysics software. The outcome of the current study puts forward OG-JFET as a new platform for biosensing applications. Full article
(This article belongs to the Special Issue Advanced Field-Effect Sensors)
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14 pages, 1388 KiB  
Article
Parallel Potentiometric and Capacitive Response in a Water-Gate Thin Film Transistor Biosensor at High Ionic Strength
by Hadi AlQahtani, Abdullah Alswieleh, Ibrahim Al-Khurayyif, Saad AlGarni and Martin Grell
Sensors 2021, 21(16), 5618; https://0-doi-org.brum.beds.ac.uk/10.3390/s21165618 - 20 Aug 2021
Cited by 6 | Viewed by 2494
Abstract
We show that an SnO2-based water-gate thin film transistor (WGTFT) biosensor responds to a waterborne analyte, the spike protein of the SARS-CoV-2 virus, by a parallel potentiometric and capacitive mechanism. We draw our conclusion from an analysis of transistor output characteristics, [...] Read more.
We show that an SnO2-based water-gate thin film transistor (WGTFT) biosensor responds to a waterborne analyte, the spike protein of the SARS-CoV-2 virus, by a parallel potentiometric and capacitive mechanism. We draw our conclusion from an analysis of transistor output characteristics, which avoids the known ambiguities of the common analysis based on transfer characteristics. Our findings contrast with reports on organic WGTFT biosensors claiming a purely capacitive response due to screening effects in high ionic strength electrolytes, but are consistent with prior work that clearly shows a potentiometric response even in strong electrolytes. We provide a detailed critique of prior WGTFT analysis and screening reasoning. Empirically, both potentiometric and capacitive responses can be modelled quantitatively by a Langmuir‒Freundlich (LF) law, which is mathematically equivalent to the Hill equation that is frequently used for biosensor response characteristics. However, potentiometric and capacitive model parameters disagree. Instead, the potentiometric response follows the Nikolsky-Eisenman law, treating the analyte ‘RBD spike protein’ as an ion carrying two elementary charges. These insights are uniquely possible thanks to the parallel presence of two response mechanisms, as well as their reliable delineation, as presented here. Full article
(This article belongs to the Special Issue Advanced Field-Effect Sensors)
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14 pages, 4387 KiB  
Article
Highly Sensitive and Transparent Urea-EnFET Based Point-of-Care Diagnostic Test Sensor with a Triple-Gate a-IGZO TFT
by Seong-Kun Cho and Won-Ju Cho
Sensors 2021, 21(14), 4748; https://0-doi-org.brum.beds.ac.uk/10.3390/s21144748 - 12 Jul 2021
Cited by 6 | Viewed by 2608
Abstract
In this study, we propose a highly sensitive transparent urea enzymatic field-effect transistor (EnFET) point-of-care (POC) diagnostic test sensor using a triple-gate amorphous indium gallium zinc oxide (a-IGZO) thin-film pH ion-sensitive field-effect transistor (ISFET). The EnFET sensor consists of a urease-immobilized tin-dioxide (SnO [...] Read more.
In this study, we propose a highly sensitive transparent urea enzymatic field-effect transistor (EnFET) point-of-care (POC) diagnostic test sensor using a triple-gate amorphous indium gallium zinc oxide (a-IGZO) thin-film pH ion-sensitive field-effect transistor (ISFET). The EnFET sensor consists of a urease-immobilized tin-dioxide (SnO2) sensing membrane extended gate (EG) and an a-IGZO thin film transistor (TFT), which acts as the detector and transducer, respectively. To enhance the urea sensitivity, we designed a triple-gate a-IGZO TFT transducer with a top gate (TG) at the top of the channel, a bottom gate (BG) at the bottom of the channel, and a side gate (SG) on the side of the channel. By using capacitive coupling between these gates, an extremely high urea sensitivity of 3632.1 mV/pUrea was accomplished in the range of pUrea 2 to 3.5; this is 50 times greater than the sensitivities observed in prior works. High urea sensitivity and reliability were even obtained in the low pUrea (0.5 to 2) and high pUrea (3.5 to 5) ranges. The proposed urea-EnFET sensor with a triple-gate a-IGZO TFT is therefore expected to be useful for POC diagnostic tests that require high sensitivity and high reliability. Full article
(This article belongs to the Special Issue Advanced Field-Effect Sensors)
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16 pages, 4837 KiB  
Article
Highly Sensitive Magnesium-Doped ZnO Nanorod pH Sensors Based on Electrolyte–Insulator–Semiconductor (EIS) Sensors
by Ensaf Mohammed Al-Khalqi, Muhammad Azmi Abdul Hamid, Naif H. Al-Hardan and Lim Kar Keng
Sensors 2021, 21(6), 2110; https://0-doi-org.brum.beds.ac.uk/10.3390/s21062110 - 17 Mar 2021
Cited by 16 | Viewed by 3099
Abstract
For highly sensitive pH sensing, an electrolyte insulator semiconductor (EIS) device, based on ZnO nanorod-sensing membrane layers doped with magnesium, was proposed. ZnO nanorod samples prepared via a hydrothermal process with different Mg molar ratios (0–5%) were characterized to explore the impact of [...] Read more.
For highly sensitive pH sensing, an electrolyte insulator semiconductor (EIS) device, based on ZnO nanorod-sensing membrane layers doped with magnesium, was proposed. ZnO nanorod samples prepared via a hydrothermal process with different Mg molar ratios (0–5%) were characterized to explore the impact of magnesium content on the structural and optical characteristics and sensing performance by X-ray diffraction analysis (XRD), atomic force microscopy (AFM), and photoluminescence (PL). The results indicated that the ZnO nanorods doped with 3% Mg had a high hydrogen ion sensitivity (83.77 mV/pH), linearity (96.06%), hysteresis (3 mV), and drift (0.218 mV/h) due to the improved crystalline quality and the surface hydroxyl group role of ZnO. In addition, the detection characteristics varied with the doping concentration and were suitable for developing biomedical detection applications with different detection elements. Full article
(This article belongs to the Special Issue Advanced Field-Effect Sensors)
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12 pages, 3440 KiB  
Article
A Graphene-Based Enzymatic Biosensor Using a Common-Gate Field-Effect Transistor for L-Lactic Acid Detection in Blood Plasma Samples
by Ariadna Schuck, Hyo Eun Kim, Júlia Konzen Moreira, Priscila Schmidt Lora and Yong-Sang Kim
Sensors 2021, 21(5), 1852; https://0-doi-org.brum.beds.ac.uk/10.3390/s21051852 - 06 Mar 2021
Cited by 20 | Viewed by 4295
Abstract
Lactate is an important organic molecule that is produced in excess during anaerobic metabolism when oxygen is absent in the human organism. The concentration of this substance in the body can be related to several medical conditions, such as hemorrhage, respiratory failure, and [...] Read more.
Lactate is an important organic molecule that is produced in excess during anaerobic metabolism when oxygen is absent in the human organism. The concentration of this substance in the body can be related to several medical conditions, such as hemorrhage, respiratory failure, and ischemia. Herein, we describe a graphene-based lactate biosensor to detect the concentrations of L-lactic acid in different fluids (buffer solution and plasma). The active surface (graphene) of the device was functionalized with lactate dehydrogenase enzyme using different substances (Nafion, chitosan, and glutaraldehyde) to guarantee stability and increase selectivity. The devices presented linear responses for the concentration ranges tested in the different fluids. An interference study was performed using ascorbic acid, uric acid, and glucose, and there was a minimum variation in the Dirac point voltage during detection of lactate in any of the samples. The stability of the devices was verified at up to 50 days while kept in a dry box at room temperature, and device operation was stable until 12 days. This study demonstrated graphene performance to monitor L-lactic acid production in human samples, indicating that this material can be implemented in more simple and low-cost devices, such as flexible sensors, for point-of-care applications. Full article
(This article belongs to the Special Issue Advanced Field-Effect Sensors)
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Review

Jump to: Editorial, Research

23 pages, 6862 KiB  
Review
Recent Advances in Photo−Activated Chemical Sensors
by Dong Hyun Lee and Hocheon Yoo
Sensors 2022, 22(23), 9228; https://0-doi-org.brum.beds.ac.uk/10.3390/s22239228 - 27 Nov 2022
Cited by 3 | Viewed by 1940
Abstract
Gas detectors have attracted considerable attention for monitoring harmful gases and air pollution because of industry development and the ongoing interest in human health. On the other hand, conventional high−temperature gas detectors are unsuitable for safely detecting harmful gases at high activation temperatures. [...] Read more.
Gas detectors have attracted considerable attention for monitoring harmful gases and air pollution because of industry development and the ongoing interest in human health. On the other hand, conventional high−temperature gas detectors are unsuitable for safely detecting harmful gases at high activation temperatures. Photo−activated gas detectors improve gas sensing performance at room temperature and enable low−power operation. This review presents a timely overview of photo−activated gas detectors that use illuminated light instead of thermal energy. Illuminated light assists in gas detection and is classified as visible or ultraviolet light. The research on photo−activated gas detectors is organized according to the type of gas that can be intensively detected. In addition, a development strategy for advancing photo−activated gas detectors is discussed. Full article
(This article belongs to the Special Issue Advanced Field-Effect Sensors)
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