Editorial

3 pages, 191 KiB

Open AccessEditorial

Bioinspired Chemical Sensors and Micro-Nano Devices

by Ping Wang, Chunsheng Wu and Liujing Zhuang

Chemosensors 2022, 10(11), 456; https://doi.org/10.3390/chemosensors10110456 - 03 Nov 2022

Viewed by 1022

Biological smell and taste systems can recognize the specific chemical signals presented by various odorants and taste substances with extremely high performance, which cannot be achieved by current artificial devices [...] Full article

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

Research

Jump to: Editorial

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 - 07 Jun 2022

Cited by 7 | Viewed by 3354

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)

► Show Figures

Figure 1

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 - 02 Jun 2022

Cited by 6 | Viewed by 2640

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)

► Show Figures

Figure 1

18 pages, 2760 KiB

Open AccessArticle

An Enzyme-Based Interdigitated Electrode-Type Biosensor for Detecting Low Concentrations of H₂O₂ Vapor/Aerosol

by Farnoosh Vahidpour, Yousef Alghazali, Sevilay Akca, Gregor Hommes and Michael J. Schöning

Chemosensors 2022, 10(6), 202; https://doi.org/10.3390/chemosensors10060202 - 26 May 2022

Cited by 5 | Viewed by 2672

Abstract

This work introduces a novel method for the detection of H₂O₂ vapor/aerosol of low concentrations, which is mainly applied in the sterilization of equipment in medical industry. Interdigitated electrode (IDE) structures have been fabricated by means of microfabrication techniques. A [...] Read more.

This work introduces a novel method for the detection of H₂O₂ vapor/aerosol of low concentrations, which is mainly applied in the sterilization of equipment in medical industry. Interdigitated electrode (IDE) structures have been fabricated by means of microfabrication techniques. A differential setup of IDEs was prepared, containing an active sensor element (active IDE) and a passive sensor element (passive IDE), where the former was immobilized with an enzymatic membrane of horseradish peroxidase that is selective towards H₂O₂. Changes in the IDEs’ capacitance values (active sensor element versus passive sensor element) under H₂O₂ vapor/aerosol atmosphere proved the detection in the concentration range up to 630 ppm with a fast response time (<60 s). The influence of relative humidity was also tested with regard to the sensor signal, showing no cross-sensitivity. The repeatability assessment of the IDE biosensors confirmed their stable capacitive signal in eight subsequent cycles of exposure to H₂O₂ vapor/aerosol. Room-temperature detection of H₂O₂ vapor/aerosol with such miniaturized biosensors will allow a future three-dimensional, flexible mapping of aseptic chambers and help to evaluate sterilization assurance in medical industry. Full article

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

► Show Figures

Figure 1

11 pages, 4590 KiB

Open AccessArticle

A Cell Co-Culture Taste Sensor Using Different Proportions of Caco-2 and SH-SY5Y Cells for Bitterness Detection

by Chunlian Qin, Saisai Zhang, Qunchen Yuan, Mengxue Liu, Nan Jiang, Liujing Zhuang, Liquan Huang and Ping Wang

Chemosensors 2022, 10(5), 173; https://doi.org/10.3390/chemosensors10050173 - 05 May 2022

Cited by 8 | Viewed by 2812

Abstract

Bitter taste receptors (T2Rs) are involved in bitter taste perception, which is one of the five basic taste modalities in mammals. In this study, a cell co-culture taste sensor using different proportions of Caco-2 cells and SH-SY5Y cells was proposed. Caco-2 cells, which [...] Read more.

Bitter taste receptors (T2Rs) are involved in bitter taste perception, which is one of the five basic taste modalities in mammals. In this study, a cell co-culture taste sensor using different proportions of Caco-2 cells and SH-SY5Y cells was proposed. Caco-2 cells, which endogenously expressed the human T2R38 receptor, and SH-SY5Y cells, which endogenously expressed the human T2R16 receptor, were co-cultured. Using Caco-2 cells and SH-SY5Y cells at a constant total concentration of 40 K/mL, we designed seven mixtures with [Caco-2]/([Caco-2] + [SH-SY5Y]) ratios of 0, 20, 40, 50, 60, 80, and 100%. These mixtures were then seeded on the 16 E-plates of the electric cell-substrate impedance sensor (ECIS) for bitterness detection. Theoretically, after T2R38 ligands activation, continuous evolution profiles (CEP), with [Caco-2]/([Caco-2] + [SH-SY5Y]) ratios as the x-axis and ΔCI (Max) as the y-axis, would exhibit positive correlation property. After T2R16 ligands activation, the CEP would show negative correlation property. However, when stimulated with compounds that could activate both T2R16 and T2R38, it would show different response patterns. Full article

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

► Show Figures

Figure 1

12 pages, 2882 KiB

Open AccessArticle

Elucidation of Response Mechanism of a Potentiometric Sweetness Sensor with a Lipid/Polymer Membrane for Uncharged Sweeteners

by Zihong Ye, Tianci Ai, Xiao Wu, Takeshi Onodera, Hidekazu Ikezaki and Kiyoshi Toko

Chemosensors 2022, 10(5), 166; https://doi.org/10.3390/chemosensors10050166 - 28 Apr 2022

Cited by 6 | Viewed by 2116

Abstract

Nowadays, the utilization of a taste sensor with lipid/polymer membranes is one of the most accurate and objective ways to evaluate the tastes of solutions. However, it has been difficult to evaluate uncharged sweet substances, such as sucrose, because the conventional taste sensor [...] Read more.

Nowadays, the utilization of a taste sensor with lipid/polymer membranes is one of the most accurate and objective ways to evaluate the tastes of solutions. However, it has been difficult to evaluate uncharged sweet substances, such as sucrose, because the conventional taste sensor uses the potentiometric measurement, which is mainly based on changes in the surface electric charge density of the membrane. Previous studies have reported that a sweetness sensor called GL1 can evaluate the sweetness of sugars and sugar alcohols, and is commercially available for food, beverage, and pharmaceutical industries. However, the response mechanism of GL1 has not been fully elucidated. In this study, we focus on clarifying the effect of concentrations and types of metal ions in the conditioning solution on the response mechanism of the sweetness sensor GL1. Moreover, according to the different concentrations and types of metal ions in conditioning solutions, the complex formation and the hydrated radius were considered to influence the membrane potential measured in a reference solution and the sensor responses. The purpose of this study is to elucidate the response mechanism and improve the selectivity and sensitivity of the sweetness sensor. Full article

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

► Show Figures

Figure 1

15 pages, 4561 KiB

Open AccessArticle

Au Functionalized SnS₂ Nanosheets Based Chemiresistive NO₂ Sensors

by Ding Gu, Wei Liu, Jing Wang, Jun Yu, Jianwei Zhang, Baoyu Huang, Marina N. Rumyantseva and Xiaogan Li

Chemosensors 2022, 10(5), 165; https://doi.org/10.3390/chemosensors10050165 - 28 Apr 2022

Cited by 8 | Viewed by 2504

Abstract

Layered Au/SnS₂ nanosheet based chemiresistive-type sensors were successfully prepared by using an in situ chemical reduction method followed by the hydrothermal treatment. SEM and XRD were used to study the microscopic morphology and crystal lattice structure of the synthesis of Au/SnS₂ [...] Read more.

Layered Au/SnS₂ nanosheet based chemiresistive-type sensors were successfully prepared by using an in situ chemical reduction method followed by the hydrothermal treatment. SEM and XRD were used to study the microscopic morphology and crystal lattice structure of the synthesis of Au/SnS₂ nanomaterials. TEM and XPS characterization were further carried out to verify the formation of the Schottky barrier between SnS₂ nanosheets and Au nanoparticles. The as-fabricated Au/SnS₂ nanosheet based sensor demonstrated excellent sensing properties to low-concentrations of NO₂, and the response of the sensor to 4 ppm NO₂ at 120 °C was approximately 3.94, which was 65% higher than that of the pristine SnS₂ (2.39)-based sensor. Moreover, compared to that (220 s/520 s) of the pristine SnS₂-based sensor, the response/recovery time of the Au/SnS₂-based one was significantly improved, reducing to 42 s/127 s, respectively. The sensor presents a favorable long-term stability with a deviation in the response of less than 4% for 40 days, and a brilliant selectivity to several possible interferents such as NH₃, acetone, toluene, benzene, methanol, ethanol, and formaldehyde. The Schottky barrier that formed at the interface between the SnS₂ nanosheets and Au nanoparticles modulated the conducting channel of the nanocomposites. The “catalysis effect” and “spillover effect” of noble metals jointly improved the sensitivity of the sensor and effectively decreased the response/recovery time. Full article

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

► Show Figures

Figure 1

14 pages, 3372 KiB

Open AccessArticle

Odor Recognition of Thermal Decomposition Products of Electric Cables Using Odor Sensing Arrays

by Yuanchang Liu, Shintaro Furuno, Sosuke Akagawa, Rui Yatabe, Takeshi Onodera, Nobuyuki Fujiwara, Hidekazu Takeda, Seiichi Uchida and Kiyoshi Toko

Chemosensors 2021, 9(9), 261; https://doi.org/10.3390/chemosensors9090261 - 10 Sep 2021

Cited by 5 | Viewed by 2378

Abstract

An odor sensing system with chemosensitive resistors was used to identify the gases generated from overheated cables to prevent fire. Three different electric cables for a distribution cabinet were used. The cables had an insulation layer made of polyvinyl chloride (PVC) or cross-linked [...] Read more.

An odor sensing system with chemosensitive resistors was used to identify the gases generated from overheated cables to prevent fire. Three different electric cables for a distribution cabinet were used. The cables had an insulation layer made of polyvinyl chloride (PVC) or cross-linked polyethylene (XLPE). The heat resistance of the cables was tested by differential thermal and thermogravimetric analyses. The thermal decomposition products of the cables were investigated by gas chromatography-mass spectrometry (GC-MS). For the odor sensing system, two types of 16-channel array were used to detect the generated gases. One contains high-polarity GC stationary phase materials and the other contains GC stationary phase materials of high to low polarity. The system could distinguish among three cable samples at 270 °C with an accuracy of about 75% through both arrays trained with machine learning. Furthermore, the system could achieve a recall rate of 90% and a precision rate of 70% when the abnormal temperature was set above the cables’ allowable conductor temperature at 130 °C. The odor sensing system could effectively detect the abnormal heating of the cables before the occurrence of fire. Therefore, it is helpful for fire prediction and detection systems in factories and substations. Full article

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

► Show Figures

Figure 1

Journal Menu

Journal Browser

Bioinspired Chemical Sensors and Micro-Nano Devices

Share This Special Issue

Special Issue Editors

Special Issue Information

Keywords

Published Papers (8 papers)

Editorial

Research

Further Information

Guidelines

MDPI Initiatives

Follow MDPI