Shigeyasu Uno
Ritsumeikan University

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Electrochemical Redox Cycling Realized by Chromatography Paper-based Sensor Kenichi Fukayama; Sou Yamamoto; Shigeyasu Uno
TELKOMNIKA (Telecommunication Computing Electronics and Control) Vol 15, No 2: June 2017
Publisher : Universitas Ahmad Dahlan

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.12928/telkomnika.v15i2.6130

Abstract

In this work, we demonstrated that enhancement of electrochemical current due to redox cycling could be accomplished by paper-based biosensor without any expensive micro-fabrication process. The paper-based sensor had layered structure to generate higher current than a conventional one. We took advantage of the fact that the paper thickness was micrometer-sized (180um), and it defined the distance between two electrochemical electrodes on both sides of the paper. Experimental results showed signatures of the redox cycling, where the electrochemical current from low concentration molecules could be arbitrarily increased by decreasing the distance between electrodes. Such a structure was advantageous for detecting target molecules at very low concentration, proposing a low-cost highly-sensitive biochemcal sensor.  
Simultaneous Electrochemical Measurement using Paper Fluidic Channel on CMOS Chip Jun Eguchi; Katsuyuki Yamaoka; Shigeyasu Uno
TELKOMNIKA (Telecommunication Computing Electronics and Control) Vol 15, No 2: June 2017
Publisher : Universitas Ahmad Dahlan

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.12928/telkomnika.v15i2.6131

Abstract

This paper described the new system of biosensing using CMOS chip. The system was expected to be used in various circumstances because it was suitable for miniaturization compared to the conventional system. To conduct electrochemical measurements, the new system used paper fluidic channel set on the CMOS chip to transport solution to the on-chip electrodes. The materials of paper fluidic channel were only paper and silicone resin, and these were biocompatible. In experiment, we carried out simultaneous detection of glucose and ethanol in liquid sample solutions on the 5mm square CMOS chip and paper fluidic channel. Furthermore, this system can detect various target molecules in addition to glucose and ethanol, and increase number of simultaneous measurement by adding some more process to the paper and CMOS chip. 
Portable Electrochemical Gas Sensing System with a Paper-Based Enzyme Electrode Shogo Kawahara; Yukio Fuchigami; Shoji Shimokawa; Yousuke Nakamura; Tatsumi Kuretake; Masao Kamahori; Shigeyasu Uno
TELKOMNIKA (Telecommunication Computing Electronics and Control) Vol 15, No 2: June 2017
Publisher : Universitas Ahmad Dahlan

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.12928/telkomnika.v15i2.6142

Abstract

An unconventional portable electrochemical gas sensor composed of a smartphone, a finger-sized sensing chip and a single use paper-based enzyme electrode was proposed to detect a particular target gaseous inclusion for self-breath-analysis with ease. This attempt allowed us to monitor our physical status immediately and continuously regardless of a time, place or person due to the improved convenience, immediacy, and affordability. The custom CMOS chip with the capability of performing an amperometric determination when the power voltage supplied from the earphone jack of a smartphone was designed as an analytical device. A disposable enzyme electrode was prepared simply from a chromatography paper and a commercial carbon pencil instead of the conventional indisposable material and complex manufacturing process. The quantification of ethanol in gaseous samples was demonstrated in range from 50 to 500ppm (V/V) in accord with concentrations in exhaled breath. The response current increased linearly with increasing vapor ethanol concentration.
Potentiometric Glucose Detection by Paper-based Electrochemical Sensor on CMOS Chip Katsuyuki Yamaoka; Jun Eguchi; Shigeyasu Uno
TELKOMNIKA (Telecommunication Computing Electronics and Control) Vol 15, No 2: June 2017
Publisher : Universitas Ahmad Dahlan

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.12928/telkomnika.v15i2.6129

Abstract

This paper presents a low cost portable medical device for biochemical sensor using CMOS chip and paper-based fluidic channel. We measured a potential produced by enzyme activity of glucose between the working and reference electrode on CMOS chip. A liquid sample is transported by paper-based fluidic channel, which is made of chromatography paper and silicone resin, and consists of the area for filtering a sample (filter layer) and that for reacting enzyme (enyzme layer). The paper-based fluidic channel is used by combining CMOS chip, and the solution with glucose is dropped from top of the paper-based fluidic channel. The concentrations of glucose are detected by potentiometry (open circuit potential time). The experimental results show that the glucose concentration is measured by CMOS chip and paper-based fluidic channel.