掲載種別：研究論文（学術雑誌）   出版者・発行元：IEEE Sensors Letters  

Localized surface plasmon resonance (LSPR) technology facilitates rapid gas detection but faces challenges regarding selectivity and fabrication complexity. This study presents a pioneering method for fabricating LSPR gas sensor arrays with pixel patterns using inkjet printing. By adjusting the compositions of Au nanoparticle (AuNP)/Ag nanoparticle (AgNP) ink patterns and incorporating various fluorescent dyes, spectrum information can be gathered to enable precise gas discrimination. Specifically, we have integrated 32 units within a compact 5 times 10 mathrm{m}{{mathrm{m}}2} area to form the subpixel sensor array, thereby minimizing sensor scale and enhancing gas selectivity. In addition, principal component analysis is employed to enhance selectivity among the six common gases. Notably, this letter marks the first fabrication of LSPR gas sensor subpixel pattern arrays through inkjet printing, which combines Au/Ag nanoparticles and fluorescent pigments. Despite its limited scale, this device offers high information density. This letter on subpixel patterned LSPR gas sensor arrays introduces a novel method for sensor fabrication and demonstrates significant potential for enabling rapid, sensitive, and selective gas detection in future research endeavors.

DOI： 10.1109/LSENS.2024.3419812

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記述言語：英語   出版者・発行元：PLoS ONE  

Our previous studies indicate the abundant and diverse presence of yet-to-be-cultured microorganisms in the micropore-filtered fractions of various environmental samples. Here, we isolated a novel bacterium (designated as strain TMPK1T) from a 0.45-μm-filtered soil suspension by using a gel-filled microwell array device comprising 900 microwells and characterized its phylogenetic and physiological features. This strain showed low 16S rRNA gene sequence identities (<91%) and low average nucleotide identity values (<70%) to the closest validly described species, and belonged to a novel-family-level lineage within the order Rhodospirillales of Alphaproteobacteria. Strain TMPK1T exhibited small cell sizes (0.08–0.23 μm3) and had a high cyclopropane fatty acid content (>13%), and these characteristics were differentiated from other Rhodospirillales bacteria. A comprehensive habitability search using amplicon datasets suggested that TMPK1T and its close relatives are mainly distributed in soil and plant-associated environments. Based on these results, we propose that strain TMPK1T represents a novel genus and species named Roseiterribacter gracilis gen. nov., sp. nov. (JCM 34627T = KCTC 82790T). We also propose Roseiterribacteraceae fam. nov. to accommodate the genus Roseiterribacter.

DOI： 10.1371/journal.pone.0304366

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掲載種別：研究論文（学術雑誌）   出版者・発行元：IEEE Sensors Journal  

Surface-enhanced Raman scattering (SERS) gas sensing is important in various fields, including environmental monitoring, health diagnosis, and food safety. We used a one-step sputtering method to fabricate an SERS gas sensor to detect and recognize volatile organic aromatic compound (VOAC) vapors using close-set and open-set models. Four pure VOAC vapors (acetophenone, anisole, anethole, and benzaldehyde) and mixtures of the compounds were analyzed using the SERS sensor. The normalized Raman spectra of the target compounds were preprocessed using the principal component analysis (PCA) and discrete wavelet transform (DWT) dimension-reduction methods before analysis. For closed-set recognition, three classical classifiers [naive Bayesian classifier (NBC), support vector machines (SVMs) classifier, and random forest classifier (RFC)] were used to identify three vapor datasets (normalized, PCA-, and DWT-based datasets). The best accuracy (99.4%) was achieved using the PCA-based dataset by SVM classifier. For open-set recognition, the dataset was first imported into a convolutional neural network (CNN) to extract features, and then, three open-set recognition models [Softmax, Openmax, and class anchor clustering (CAC)] were applied. The open-set classifier performances for different open problems were assessed using the dataset openness values of 0.0871, 0.1835, and 0.3333. CAC gave an area under receiver operating characteristic (AUROC) of 0.846 for discriminating between known and unknown samples and an accuracy of 94.5% for classifying the known vapor samples at an openness of 0.0871. The SERS sensor effectively detected vapor-phase compounds and could distinguish between the target compounds in both close-set and open-set recognition scenarios.

DOI： 10.1109/JSEN.2024.3383053

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掲載種別：研究論文（学術雑誌）   出版者・発行元：IEEJ Transactions on Electrical and Electronic Engineering  

Surface-Enhanced Raman Scattering (SERS) technique is used to fabricate the gas sensor, which is developed for the visualization of the spatial distribution of gas evaporating from odor source. The 3 × 3 SERS sensor array is put on the odor source and then scanned by the home-made detection system to obtain the Raman spectra of the odor. The intensities of the characteristic peaks from the collected spectra are used to draw a heatmap graph. After the heatmap graph is processed by the noise reduction, the localization of the odor source can be clearly identified through the resulting graph. © 2024 Institute of Electrical Engineer of Japan and Wiley Periodicals LLC.

DOI： 10.1002/tee.23988

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Sensors  

The spatial distribution of gas emitted from an odor source provides valuable information regarding the composition, size, and localization of the odor source. Surface-enhanced Raman scattering (SERS) gas sensors exhibit ultra-high sensitivity, molecular specificity, rapid response, and large-area detection. In this paper, a SERS gas sensor array was developed for visualizing the spatial distribution of gas evaporated from benzaldehyde and 4-ethylbenzaldehyde odor sources. The SERS spectra of the gas were collected by scanning the sensor array using an automatic detection system. The non-negative matrix factorization algorithm was employed to extract feature and concentration information at each spot on the sensor array. A heatmap image was generated for visualizing the gas spatial distribution using concentration information. Gaussian fitting was applied to process the image for localizing the odor source. The size of the odor source was estimated using the processed image. Moreover, the spectra of benzaldehyde, 4-ethylbenzaldehyde, and their gas mixture were simultaneously detected using one SERS sensor array. The feature information was recognized using a convolutional neural network with an accuracy of 98.21%. As a result, the benzaldehyde and 4-ethylbenzaldehyde odor sources were identified and visualized. Our research findings have various potential applications, including odor source localization, environmental monitoring, and healthcare.

DOI： 10.3390/s24030790

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出版者・発行元：Proceedings of IEEE Sensors  

Microbial volatile organic compounds (MVOCs) can serve as a diagnostic tool for assessing the respiratory status of microorganisms. Localized surface plasmon resonance (LSPR) sensors are noted for their rapid response and straightforward operation; however, they often struggle to provide specific information about the detected substances and to differentiate between gas types. In contrast, gas sensors utilizing surface-enhanced Raman spectroscopy (SERS) technology offer excellent selectivity and can generate unique 'fingerprint' signals, enabling easy identification and distinction of various gas molecules. Integrating these two technologies promises to enhance the visualization of volatile organic compound distributions both more effectively and expeditiously.

DOI： 10.1109/SENSORS60989.2024.10785178

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Sensors  

Odor information fills every corner of our lives yet obtaining its spatiotemporal distribution is a difficult challenge. Localized surface plasmon resonance has shown good sensitivity and a high response/recovery speed in odor sensing and converts chemical information such as odor information into optical information, which can be captured by charge-coupled device cameras. This suggests that the utilization of localized surface plasmon resonance has great potential in two-dimensional odor trace visualization. In this study, we developed a two-dimensional imaging system based on backside scattering from a localized surface plasmon resonance substrate to visualize odor traces, providing an intuitive representation of the spatiotemporal distribution of odor, and evaluated the performance of the system. In comparative experiments, we observed distinct differences between odor traces and disturbances caused by environmental factors in differential images. In addition, we noted changes in intensity at positions corresponding to the odor traces. Furthermore, for indoor experiments, we developed a method of finding the optimal capture time by comparing changes in differential images relative to the shape of the original odor trace. This method is expected to assist in the collection of spatial information of unknown odor traces in future research.

DOI： 10.3390/s23239525

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記述言語：その他   掲載種別：研究論文（学術雑誌）   出版者・発行元：IEEE Sensors Letters  

Visualization of gaseous chemical substances, such as odors, is very challenging, and few studies are being conducted to address this issue. These odor visualization technologies are expected to be more beneficial for various applications, such as detecting hazardous or human relating gas source localization. Currently, semiconductor gas sensors are commonly used for gas measurements; however, these sensors have disadvantages, such as slow response time and inability to detect multiple types of gases. Furthermore, it is difficult to understand how gases are distributed in space. Thus, we have developed a gas sensor utilizing localized surface plasmon resonance (LSPR). LSPR gas sensors enable real-time, high-speed response and recovery, and by analyzing wavelength information using a hyperspectral camera, gas imaging and identification become possible. In this letter, we conducted experiments on visualizing the spatiotemporal distribution of multiple gases and identifying gas space through the analysis of spectral information using a 2-D LSPR gas sensor and a hyperspectral camera. As a result, we successfully visualized and identified the distribution of each gas in a situation where multiple gases were present by performing principal component analysis analysis on the spectral data obtained from hyperspectral images.

DOI： 10.1109/LSENS.2023.3301847

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記述言語：その他   掲載種別：研究論文（学術雑誌）   出版者・発行元：IEEE Sensors Letters  

Localized surface plasmon resonance (LSPR) offers rapid gas detection but faces selectivity and fabrication complexity challenges. This letter reports a method of fabricating LSPR gas sensor arrays with pixel patterns by inkjet printing. We developed Au/Ag nanoparticles ink with different compositions to collect spectrum information for accurate gas discrimination. In addition, principal component analysis (PCA) is used to realize the selectivity among four common gases that we often encounter in our daily lives. For the first time, this work demonstrates the fabrication of LSPR gas sensors through inkjet printing. Based on the LSPR phenomenon for gas detection, it shows great potential for rapid, sensitive, and selective gas detection for future research.

DOI： 10.1109/LSENS.2023.3300820

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記述言語：その他   掲載種別：研究論文（学術雑誌）   出版者・発行元：Japanese Journal of Applied Physics  

This study aims to develop a microfluidic-based taste sensor for detecting time-dependent human taste sensations. Lipid polymer membranes were welded to perforated polycarbonate films with organic solvents to monitor the adsorption and desorption of taste substances to lipid polymer membranes and to physically immobilize lipid polymer membranes to withstand the pressure of a pumped liquid. A polydimethylsiloxane flow channel was bonded chemically to the polycarbonate film with the lipid polymer membrane using 3-aminopropylethoxysilane. A fabricated microfluidic-based taste sensor could measure the membrane potential change with time due to the adsorption and desorption of tannic acid, an astringency substance, onto a lipid polymer membrane. The proposed sensor could be useful as a tool for assessing the time-course changes in human taste.

DOI： 10.35848/1347-4065/acb4fa

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掲載種別：研究論文（国際会議プロシーディングス）   出版者・発行元：Proceedings of IEEE Sensors  

Microbial volatile organic compounds (MVOCs) could be detected and used to understand the metabolic state of microorganisms. The gas sensor developed using the Surface Enhanced Raman Scattering (SERS) technique possesses ultra-high sensitivity and excellent selectivity, which is suitable for detecting low-concentration and complex MVOCs. Here, an odor source is simulated as a microbial community, and a 2D SERS sensor array is utilized to visualize the odor spatial distribution and localize the odor source. The Raman spectra of the odor adsorbed onto the sensor surface are collected after scanning the sensor array. A heatmap image is obtained by using the intensities of the characteristic peaks from the acquired Raman spectra. Thus, the odor spatial distribution is presented, and the localization of the odor source is determined by the image.

DOI： 10.1109/SENSORS56945.2023.10325081

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出版者・発行元：2023 22nd International Conference on Solid-State Sensors, Actuators and Microsystems, Transducers 2023  

Surface-Enhanced Raman Scattering (SERS) technique is used to fabricate the gas sensor, which is developed for the visualization of the odor source localization. The 3 × 3 SERS sensor array is put on the odor source and then scanned by the home-made detection system to obtain the Raman spectra of the odor. The intensities of the characteristic peaks from the collected spectra are used to draw a heatmap graph. After the heatmap graph is processed by the noise reduction, the localization of the odor source can be clearly identified through the resulting graph.

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出版者・発行元：2023 22nd International Conference on Solid-State Sensors, Actuators and Microsystems, Transducers 2023  

Visualization of gaseous chemical substances such as odors is important technology, and this technology has the potential to be applied to various applications, such as searching for people at disaster sites and identifying hazardous materials. As an alternative technology to olfaction, semiconductor gas sensors are currently used to measure gases, but these sensors have problems such as slow response and slow sensor recovery, and it is also difficult to measure spatial distribution. We utilized, gas sensors using localized surface plasmon resonance (LSPR) gas sensor which have a real-time, fast response and fast recovery, making it possible to perform gas imaging and identification. Here, experiments were conducted to visualize and identify the spatiotemporal distribution of multiple gases using an 2D LSPR gas sensor and a hyperspectral camera.

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Frontiers in Microbiology  

In order to exploit the microbes present in the environment for their beneficial resources, effective selection and isolation of microbes from environmental samples is essential. In this study, we fabricated a gel-filled microwell array device using resin for microbial culture. The device has an integrated sealing mechanism that enables high-density isolation based on the culture of microorganisms; the device is easily manageable, facilitating observation using bright-field microscopy. This low-cost device made from polymethyl methacrylate (PMMA)/polyethylene terephthalate (PET) has 900 microwells (600 μm × 600 μm × 700 μm) filled with a microbial culture gel medium in glass slide-sized plates. It also has grooves for maintaining the moisture content in the micro-gel. The partition wall between the wells has a highly hydrophobic coating to inhibit microbial migration to neighboring wells and to prevent exchange of liquid substances. After being hermetically sealed, the device can maintain moisture in the agarose gels for 7 days. In the bacterial culture experiment using this device, environmental bacteria were isolated and cultured in individual wells after 3 days. Moreover, the isolated bacteria were then picked up from wells and re-cultured. This device is effective for the first screening of microorganisms from marine environmental samples.

DOI： 10.3389/fmicb.2022.1031439

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記述言語：その他   掲載種別：研究論文（学術雑誌）   出版者・発行元：npj Flexible Electronics  

A method was used to fabricate a fully inkjet-printed gas sensor matrix on photographic paper. An electrode matrix comprising 36 interdigital electrodes in a high-density layout that is easy to integrate has been fabricated using a combination of insulating ink and commercial silver ink. Molecular-imprinted polymer (MIP) inks were then made using a simple solution mixing method, and these inks were printed together with carbon black ink on the electrode matrix to complete production of the sensor. Finally, experimental dynamic sensing of volatile organic compounds verifies that for detection of gases corresponding to the MIP template molecules, the MIP layer offers improvements in both sensitivity and selectivity when compared with non-imprinted polymer layers. The matrix can produce a response of more than 20% to 3 ppm propenoic acid gas through adjustment of the printing times for the carbon black layer and the MIP layer.

DOI： 10.1038/s41528-022-00168-6

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記述言語：日本語   出版者・発行元：NPO法人 環境バイオテクノロジー学会  

DOI： 10.50963/jenvbio.22.1_69

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.3390/s21165546

記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1128/MRA.00393-21

記述言語：その他   掲載種別：研究論文（学術雑誌）  

Chemiresistor sensor matrix prepared by full-printing processes
Herein, we report a novel full printing process for fabricating chemiresistor gas sensor matrixes on photographic paper with an inkjet printer. Sensor matrices, which can increase a number of sensors significantly compared to a serial sensor array, were printed on one piece of A4 photographic paper. Each sensor matrix contains 36 interdigital electrodes in an area of less than 11 mm2, which greatly improves the density of the sensor. The basic architecture of the sensor matrix is electrodes that row and column intersecting. In order to insulate the row and column electrodes from meeting each other, an insulating layer needs to be fabricated at the point of intersection between the row and column electrodes. The insulation layer was produced by adjusting the number of printing passes and shape of the printing pattern of color pigment ink. Carbon black (CB) was used to form a chemosensitive composite by changing its resistivity with a specific polymer for the preparation of sensing material. In order to make the sensing material can be printed, it is necessary to disperse CB first. CB was dispersed in aqueous solution with sodium dodecyl sulfate added as a surfactant to lower the surface tension, which enabled printing of CB using an inkjet printer. Some polymers have certain adsorption characteristics for gases. According to the different gas properties, the adsorption characteristics are also different. By adding polyethylene glycol polymer to the CB layer, the response to four gases with different properties is improved. Compared with the drop coating, the full-printing sensors not only reduces the production time significantly, but also improves the gas response magnitude to ethanol by about three times. The results demonstrate that the developed sensor can be used as a low cost, disposable, and easily printable chemical sensor.

DOI： 10.1088/2058-8585/abec19

記述言語：その他   掲載種別：研究論文（その他学術会議資料等）  

DOI： 10.1109/SENSORS47125.2020.9278605

記述言語：その他   掲載種別：研究論文（その他学術会議資料等）  

2D LSPR gas sensor with Au/Ag core-shell structure coated by fluorescent dyes
LSPR (Localized Surface Plasmon Resonance) based 2D (Two-dimensional) gas sensor system which can measure and identify multi-gases with high spatial resolution have been developed. The gas sensor detects optical changes promoted by the gas on the LSPR substrate with hyperspectral camera. Basically, LSPR gas sensor does not have a molecular selectivity, then the identification of gas species is difficult. To overcome the disadvantage, LSPR substrates based on Au/Ag core-shell structure with spectral gas-discriminating ability through optical interaction were fabricated by spin coating fluorescent dyes. Using the LSPR coupled with fluorescent dyes, this sensor provides rich spectral information about the detecting molecules and can discriminates gas species.

DOI： 10.1109/SENSORS47125.2020.9278828

記述言語：その他   掲載種別：研究論文（その他学術会議資料等）  

DOI： 10.1109/SENSORS47125.2020.9278909

記述言語：英語  

Microfabricated electrochemical sensing devices
Electrochemistry provides possibilities to realize smart microdevices of the next generation with high functionalities. Electrodes, which constitute major components of electrochemical devices, can be formed by various microfabrication techniques, and integration of the same (or different) components for that purpose is not difficult. Merging this technique with microfluidics can further expand the areas of application of the resultant devices. To augment the development of next generation devices, it will be beneficial to review recent technological trends in this field and clarify the directions required for moving forward. Even when limiting the discussion to electrochemical microdevices, a variety of useful techniques should be considered. Therefore, in this review, we attempted to provide an overview of all relevant techniques in this context in the hope that it can provide useful comprehensive information.

DOI： 10.1039/c9lc01112a

記述言語：その他   掲載種別：研究論文（その他学術会議資料等）  

2D LSPR multi gas sensor array with 4-segmented subpixel using Au/Ag core shell structure
LSPR (Localized Surface Plasmon Resonance) based 2D (2 Dimensional) gas imaging sensor system which can capture spatial distribution of each constituent of mixed gas have been developed. The gas image sensor detects the gas promoted optical changes occurred on the LSPR substrate by CCD camera. Basically, LSPR gas sensor does not have a molecular selectivity, then the identification of gas species is difficult. To overcome the disadvantage, pixelated LSPR substrate based on Au/Ag core-shell structure which has different gas response properties is fabricated by photo-induced metal growth by mask-less exposure system using a commercial video projector.

DOI： 10.1109/SENSORS43011.2019.8956635

記述言語：その他   掲載種別：研究論文（その他学術会議資料等）  

DOI： 10.1109/SENSORS43011.2019.8956884

記述言語：その他   掲載種別：研究論文（その他学術会議資料等）  

Invisible Odor Trace Tracking with LSPR based High Speed Gas Sensor Robot System
Various odor robots have been developed for finding gas sources. However, the response speed of sensors is now a major limit for the promotion of odor robot using chemical substances information. In this research, we have developed a robot equipped with two LSPR (Localized Surface Plasmon Resonance) gas sensor module that can quickly respond to gas molecules at a high speed of above 25 Hz and set a specific algorithm for tracking the invisible odor line on the ground.

DOI： 10.1109/SENSORS43011.2019.8956599

記述言語：その他   掲載種別：研究論文（その他学術会議資料等）  

DOI： 10.1109/SENSORS43011.2019.8956795

記述言語：その他   掲載種別：研究論文（その他学術会議資料等）  

DOI： 10.1109/TRANSDUCERS.2019.8808512

記述言語：その他   掲載種別：研究論文（その他学術会議資料等）  

Odor Trace Visualization by Mobile Robot Equipped with Two-Dimensional LSPR Gas Sensor
This paper presents a Localized Surface Plasmon Resonance (LSPR) based high speed gas sensor module for gas sensing applications, including visualization of invisible odor trail. Innovative claims include: (1) the use of a double layer film with Au/Ag nanoparticles for gas detection; (2) high speed response characteristic; and (3) visualization of odor trail pattern with high spatial resolution. The results show a significant change in reflection light with ethanol vapor; response speed of 1 second; and a clear image of visualized odor trail of letter "Q" of a 3 mm line width.

DOI： 10.1109/TRANSDUCERS.2019.8808400

記述言語：その他   掲載種別：研究論文（その他学術会議資料等）  

Gas Visualization with Photo-Induced 2D Pixel Patterned Au/Ag Core-Shell LSPR Imaging Device by Mask-Less Exposure System
Visualization of the distribution of various gases makes us possible to recognize environmental circumstances, e.g., localization of dangerous chemical sources or human body odorants in the case of disaster scene. Localized surface plasmon resonance (LSPR) can detect various gases with changes of surrounding dielectric constant, and can be used gas sensor with high response / recovery speed and high spatial resolution, i.e., 2 dimensional LSPR gas sensor gas work as a gas image sensor device. The gas image sensor detects the gas distribution occurred on the LSPR substrate by an ordinal image sensor. The general LSPR gas sensor, however, does not have a molecular selectivity, then the identification of gas species is difficult. To overcome such disadvantages, pixelated LSPR substrate based on Au/Ag core-shell structure is fabricated by photo-induced growth by mask-less exposure system using a commercial video projector.

DOI： 10.1109/TRANSDUCERS.2019.8808591

記述言語：その他   掲載種別：研究論文（その他学術会議資料等）  

DOI： 10.1109/ISOEN.2019.8823230

記述言語：その他   掲載種別：研究論文（その他学術会議資料等）  

DOI： 10.1109/ISOEN.2019.8823375

記述言語：その他   掲載種別：研究論文（その他学術会議資料等）  

Probe gas sensing system based on reflected light detection from localized surface plasmon resonance
The present study explored a probe type gas detection system which can be used to detect the gas conveniently. The gas sensing mechanism is utilizing Localized Surface Plasmon Resonance (LSPR) sensor which based on the reflected light change caused by the refractive index changes of gas where exposing to the metal nanoparticles layer. The LSPR layer was prepared by vacuum sputtering of AuNPs on a glass substrate, growing in silver growth solution and consequently thermal annealing. An optical system which composed of fiber probe, light source and spectrometer was developed to detect the change of reflected light. It was found that compared with incident light irradiating from metal nanoparticles side, glass side could obtain clearer spectra peak. In addition, a LSPR sensor which had 5 hours silver growth time has the best response to acetic acid gas. This work demonstrated that the reflection detection system has a great potential in gas detecting area.

DOI： 10.1109/ISOEN.2019.8823157

記述言語：その他   掲載種別：研究論文（その他学術会議資料等）  

DOI： 10.1109/ISOEN.2019.8823275

記述言語：その他  

DOI： 10.1016/B978-0-12-815409-0.00018-8

記述言語：その他   掲載種別：研究論文（その他学術会議資料等）  

DOI： 10.1109/ICSENS.2018.8589830

記述言語：その他   掲載種別：研究論文（その他学術会議資料等）  

DOI： 10.1109/ICSENS.2018.8589909

記述言語：その他   掲載種別：研究論文（その他学術会議資料等）  

DOI： 10.1109/ICSENS.2018.8589717

記述言語：英語   掲載種別：研究論文（学術雑誌）  

A robot equipped with a high-speed LSPR gas sensor module for collecting spatial odor information from on-ground invisible odor sources
Improving the efficiency of detecting the spatial distribution of gas information with a mobile robot is a great challenge that requires rapid sample collection, which is basically determined by the speed of operation of gas sensors. The present work developed a robot equipped with a highspeed gas sensor module based on localized surface plasmon resonance. The sensor module is designed to sample gases from an on-ground odor source, such as a footprint material or artificial odor marker, via a fine sampling tubing. The tip of the sampling tubing was placed close to the ground to reduce the sampling time and the effect of natural gas diffusion. On-ground ethanol odor sources were detected by the robot at high resolution (i.e., 2.5 cm when the robot moved at 10 cm/s), and the reading of gas information was demonstrated experimentally. This work may help in the development of environmental sensing robots, such as the development of odor source mapping and multirobot systems with pheromone tracing.

DOI： 10.1021/acssensors.8b00214

記述言語：その他   掲載種別：研究論文（学術雑誌）  

DOI： 10.1016/j.snb.2017.11.128

記述言語：その他   掲載種別：研究論文（その他学術会議資料等）  

Odorants measurement using hyperspectral imaging and PVC film including multi fluorescent probes
Odor imaging sensor was developed with odorants sensing mechanism based on the complicated fluorescence interactions between the multi-fluorescent-probes and odorants. In this research, poly vinyl chloride (PVC) films including various fluorescent probe were developed, and fluorescence properties of the film were investigated. Using the multi fluorescent probe film, fluorescence intensity change spectrum to various odorants was measured, and odorants could be clustered by their chemical structure by multi-variate analyses of hyper spectra images.

DOI： 10.1109/ICSENS.2017.8234328

記述言語：その他   掲載種別：研究論文（その他学術会議資料等）  

DOI： 10.1109/TRANSDUCERS.2017.7994313

記述言語：その他   掲載種別：研究論文（学術雑誌）  

Review of Microfluidic Devices for On-Chip Chemical Sensing
Microfluidic techniques can be a basis to realize user-friendly microanalytical devices of high performance. Required operations include injection of solutions to reaction chambers, volume measurement, and mixing of solutions. For this purpose, the use of surface tension is attractive. In hydrophobic flow channels, solutions can be moved stably in the form of plugs. Otherwise, solutions can be transported by capillary action in a hydrophilic flow channel and stopped at a hydrophobic valve. The valve can be opened autonomously by switching the mixed potential by wetting a zinc electrode formed in a controlling flow channel. In this review paper, we introduce some of our microfluidic devices particularly focusing on devices that work based on surface tension.

DOI： 10.1002/ecj.11944

記述言語：その他   掲載種別：研究論文（その他学術会議資料等）  

DOI： 10.1109/ICSENS.2016.7808850

記述言語：その他   掲載種別：研究論文（その他学術会議資料等）  

DOI： 10.1109/ICSENS.2016.7808604

記述言語：その他   掲載種別：研究論文（その他学術会議資料等）  

DOI： 10.1109/ICSENS.2016.7808660

記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.3390/s16111974

記述言語：英語   掲載種別：研究論文（学術雑誌）  

Microfluidic Separation of Redox Reactions for Coulometry Based on Metallization at the Mixed Potential
Coulometric detection of an analyte in a solution at nanoliter scale was conducted by having redox reactions proceed simultaneously on a platinum electrode. The analyte was oxidized on a part of the electrode in one flow channel and silver was deposited on an array of circular microelectrodes formed in another flow channel at a mixed potential. Coulometric determination of the deposited silver showed a steep change in the generated charge as a result of the complete oxidation of silver. The short measurement time after the start of the coulometry suppressed the increase in background charge, resulting in significant lowering of the detection limit. The lower detection limit for H O was 30 nM (3σ). To improve selectivity and minimize the influence of coexisting interferents, the shifting of the mixed potential, application of a permselective membrane, and electrochemical elimination of the interferents were effective modifications. 2 2

DOI： 10.1021/acs.analchem.6b01234

記述言語：その他   掲載種別：研究論文（学術雑誌）  

Electrochemical Bubble-Based Bidirectional Microfluidic Transport
With the aim of application to biochemical analyses, efficient bidirectional microfluidic transport was achieved through the reversible electrochemical production and shrinkage of hydrogen bubbles. A three-electrode system with a platinum black working electrode, a Ag/AgCl reference electrode, and a platinum auxiliary electrode was incorporated into a poly(dimethylsiloxane) structure containing the necessary flow channels and compartments. The influence of the electrode and flow channel structures on the operation of the system was investigated. The production and shrinkage of bubbles was achieved by applying appropriate potentials to the working electrode, which minimized the influence of spontaneous shrinkage resulting from the oxidizing effect of dissolved oxygen. Device performance depended on the structure of the working electrode, meaning that further optimization will be necessary. The device was shown to withdraw solution through a minimally invasive needle and to process liquid plugs in a microfluidic system.

DOI： 10.1021/acssensors.5b00059

記述言語：その他   掲載種別：研究論文（学術雑誌）  

DOI： 10.1016/j.precisioneng.2013.05.008

記述言語：その他   掲載種別：研究論文（学術雑誌）  

Droplet-based microfluidic sensing system for rapid fish freshness determination
A microfluidic device was constructed for on-site determination of fish freshness by using adenosine-5′-triphosphate (ATP) concentration as an indicator of freshness. In the device, extracts from fish and reagent solutions were processed in the form of droplets separated by air. The volumes of the droplets of the extract solution, a solution containing enzyme substrates, and a washing buffer solution were measured in branched flow channels. To simplify the structure and procedure for mixing solutions, a wider portion was formed in one flow channel to merge the droplets. A row of droplets was ejected from each of three branched flow channels, merged in the wider portion, and transported to a sensing region located downstream. ATP was detected using two enzymatic reactions involving glycerol kinase (GK) and glycerol-3-phosphate oxidase (G3PO). A linear relationship between the generated current and ATP concentration was confirmed, and ATP detection from jack mackerel extracts was carried out. A distinct change in the current was observed with the fresh extracts as in the case of standard solutions. The obtained data correlated well with those obtained by high-performance liquid chromatography (HPLC). © 2012 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.snb.2012.05.043

記述言語：その他   掲載種別：研究論文（学術雑誌）  

Miniaturized shape memory alloy pumps for stepping microfluidic transport
A shape memory alloy (SMA) actuator and a polydimethylsiloxane (PDMS) elastic tube were used to realize a simple pump. A liquid plug in a flow channel could be moved forward and backward reversibly by exploiting the shape memory properties of the actuator. Two SMA sheets were used to create a peristaltic pump capable of moving a solution forward and backward over a long distance. The stepping transport caused by applying pulses of electric power facilitated the adjustment of the plug's position. Manipulations such as volume measurement and the merging of two plugs were demonstrated using a microfluidic device with a T-junction. © 2012 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.snb.2011.12.085

記述言語：英語   掲載種別：研究論文（学術雑誌）  

Coulometric detection of components in liquid plugs by microfabricated flow channel and electrode structures
Coulometry has been demonstrated to be effective for determining the analyte in a liquid plug on the nanoliter-scale confined in a flow channel. A plug prepared in a rhombus structure of an auxiliary flow channel was placed on a thin-film three-electrode system, and hydrogen peroxide was detected as a model analyte. Under a fixed potential, the current decayed rapidly, particularly in shallow flow channels, thus making reproducible amperometric detection difficult. On the other hand, the increasing charge during coulometry facilitated the measurements. A constricted flow channel structure with an array of platinum strips for the working electrode was effective at efficiently consuming the analyte to improve the sensitivity and lower the detection limit. Compared to the case of a single short working electrode with the same area, a 4-fold increase in sensitivity was observed for the best combination of flow channel height and interstrip distance. With an increase in the generated current while maintaining the background at a low level, the detection limit was lowered from 1.3 μM to 410 nM using working electrodes with the same area. Furthermore, the processing of solutions containing l-glutamate or l-glutamate oxidase and the detection of l-glutamate were demonstrated. © 2010 American Chemical Society.

DOI： 10.1021/ac102289a

記述言語：英語   掲載種別：研究論文（学術雑誌）  

Engineering of capillary-like structures in tissue constructs by electrochemical detachment of cells
A major challenge in the development of functional thick tissues is the formation of vascular networks for oxygen and nutrient supply throughout the engineered tissue constructs. This study describes an electrochemical approach for fabrication of capillary-like structures, precisely aligned within micrometer distances, whose internal surfaces are covered with vascular endothelial cells. In this approach, an oligopeptide containing a cell adhesion domain (RGD) in the center and cysteine residues at both ends was designed. Cysteine has a thiol group that adsorbs onto a gold surface via a gold-thiolate bond. The cells attached to the gold surface via the oligopeptide were readily and noninvasively detached by applying a negative electrical potential and cleaving the gold-thiolate bond. This approach was applicable not only for a flat surface but also for various configurations, including cylindrical structures. By applying this approach to thin gold rods aligned in a spatially controlled manner in a perfusion culture device, human umbilical vein endothelial cells (HUVECs) were transferred onto the internal surface of capillary structures in collagen gel. In the subsequent perfusion culture, the HUVECs grew into the collagen gel and formed luminal structures, thereby forming vascular networks in vitro. © 2009 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.biomaterials.2009.11.104

記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1016/j.jbiosc.2009.06.013

記述言語：その他   掲載種別：研究論文（学術雑誌）  

Biochip with integrated pumps for plug-based sequential exchange of solutions
A novel method for exchanging solutions used in biochemical analyses and a device to carry out the exchange are proposed. An array of plugs formed using six injectors was transported in a microflow channel using a main pump located at one end of the main flow channel. The injectors and main pump were operated on the basis of the change in volume caused by the electrolysis of water. Bubbles were produced from working electrodes; these bubbles caused a diaphragm placed below the injectors to inflate and occlude the inlet of the solution reservoir. Increase in the number of bubbles caused the reservoir to inject the solution into the main flow channel in the form of a plug. Each plug was individually transported downstream to the sensing area by the main pump, which was operated in a similar manner to the injector. The device was used for the detection of a tumor marker, α-fetoprotein (AFP). Plugs of necessary solutions were individually transported to the sensing area with immobilized primary antibodies to allow antigen-antibody binding, cleaning, and detection. The fluorescence intensity from the antibodies showed clear dependence on the concentration of AFP. The immobilization of antibodies could also be carried out on-chip. © 2009 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.snb.2009.04.048

記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1021/ac800492v

記述言語：英語  

DOI： 10.1002/elps.200700581

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記述言語：英語  

CiNii Research

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記述言語：日本語   出版者・発行元：電気学会  

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記述言語：日本語   出版者・発行元：Institute of Electrical Engineers of Japan  

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記述言語：日本語   出版者・発行元：Institute of Electrical Engineers of Japan  

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記述言語：日本語   出版者・発行元：Institute of Electrical Engineers of Japan  

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記述言語：日本語   出版者・発行元：電気学会  

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記述言語：日本語   出版者・発行元：電気学会  

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記述言語：英語   掲載種別：記事・総説・解説・論説等（学術雑誌）  

Microfluidic techniques can be a basis to realize user-friendly microanalytical devices of high performance. Required operations include injection of solutions to reaction chambers, volume measurement, and mixing of solutions. For this purpose, the use of surface tension is attractive. In hydrophobic flow channels, solutions can be moved stably in the form of plugs. Otherwise, solutions can be transported by capillary action in a hydrophilic flow channel and stopped at a hydrophobic valve. The valve can be opened autonomously by switching the mixed potential by wetting a zinc electrode formed in a controlling flow channel. In this review paper, we introduce some of our microfluidic devices particularly focusing on devices that work based on surface tension.

記述言語：日本語   掲載種別：記事・総説・解説・論説等（学術雑誌）