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https://ir.swu.ac.th/jspui/handle/123456789/12174
ชื่อเรื่อง: | Contactless conductivity detector from printed circuit board for paper-based analytical systems |
ผู้แต่ง: | Chantipmanee N. Sonsa-ard T. Fukana N. Kotakanok K. Mantim T. Wilairat P. Hauser P.C. Nacapricha D. |
Keywords: | Analytic equipment Carbonates Copper corrosion Corrosion protection Electrodes Filtration Geometry Liquids Particle size analysis Plastic films Polypropylenes Potassium compounds Sensors Soils Timing circuits Capacitive coupling effects Capacitively coupled Contactless conductivity detector Hydrophobic patterns Paper-based analytical devices Poly-propylene film Printed circuit boards (PCB) Soil salinity Printed circuit boards Carbonates Corrosion Prevention Electrodes Filtration Geometry Liquids |
วันที่เผยแพร่: | 2020 |
บทคัดย่อ: | This work presents a capacitively coupled contactless conductivity detector (C4D) etched out from a printed circuit board (PCB) as potential sensor for paper-based analytical systems. Two lines of any desirable pattern forming 35-μm thick planar copper electrodes were produced on a PCB plate (40 mm × 60 mm) by photolithography. The final PCB plate was covered with polypropylene film to serve as the insulating layer for the C4D detector. The film also protected the copper electrodes from corrosion. Electrodes made in this planar geometry make the PCB-C4D suitable as sensor for flat devices such as paper-based analytical devices. For this work, plain paper strips were employed as sample reservoir and as fluidic channel without hydrophobic pattern. A dried paper strip was first placed over the sensor, followed by dispensing a fixed volume of the liquid sample onto the paper. Entrapment of the liquid sample in the paper strip leads to reproducible size and position of the detection zone of the sample liquid for the capacitive coupling effect. High precision was obtained with %RSD ≤1% (n = 18) for standard solutions of KCl. Soil suspensions could be analyzed without prior filtration by placing a drop onto the paper strip extending away from the detector zone. The paper strip filtered out soil particles at the surface of the paper. Therefore, only soil filtrate moved towards the detection zone by lateral flow. The C4D detection using paper strip showed high tolerance to soil suspension with turbidity up to 6657 NTU, offering direct analysis of soil salinity. Cleaning with moist tissue paper between samples is adequate even for dirty samples such as soil suspension. We also monitored conductivity of acid-base reaction in the microfluidic paper channels, which was later applied to the quantification of bicarbonate in water and in antacid tablet (“Soda Mint Tablet”). © 2019 Elsevier B.V. |
URI: | https://ir.swu.ac.th/jspui/handle/123456789/12174 https://www.scopus.com/inward/record.uri?eid=2-s2.0-85070643037&doi=10.1016%2fj.talanta.2019.120227&partnerID=40&md5=affb4d730d29f395134ef0126f392280 |
ISSN: | 399140 |
Appears in Collections: | Scopus 1983-2021 |
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