%0 Journal Article
%T Biocompatible and Na+-sensitive thin-film transistor for biological fluid sensing
%A Alex C. Tseng
%A Hiroto Satake
%A Kensuke Ito
%A Toshiya Sakata
%A Yuto Mori
%J Science and Technology of Advanced Materials
%D 2019
%R https://doi.org/10.1080/14686996.2019.1656516
%X ABSTRACT In this study, we develop a Na+-sensitive thin-film transistor (TFT) for a biocompatible ion sensor and investigate its cytotoxicity. A transparent amorphous oxide semiconductor composed of amorphous In¨CGa¨CZn¨Coxide (a-InGaZnO) is utilized as a channel of the Na+-sensitive TFT, which includes an indium tin oxide (ITO) film as the source and drain electrodes and a Ta2O5 thin-film gate, onto which a Na+-sensitive membrane is coated. As one of the Na+-sensitive membranes, the polyvinyl chloride (PVC) membrane with bis(12-crown-4) as the ionophore used on the TFT sensors shows good sensitivity and selectivity to changes in Na+ concentration but has high cytotoxicity owing to the leaching of its plasticizer to the solution; the plasticizer is added to solve and entrap the ionophore in the PVC membrane. On the other hand, a plasticizer-free Na+-sensitive membrane, the fluoropolysilicone (FPS) membrane with the bis(12-crown-4) ionophore, also reduces cell viability owing to the leaching of the ionophore. However, the FPS membrane with calix[4]arene as the ionophore on the gate of TFT sensors exhibits not only favorable electrical properties but also the lack of cytotoxicity. Thus, considering structural flexibility of TFTs, a platform based on TFT sensors coated with the Na+-sensitive FPS membrane containing calix[4]arene is suitable as a biocompatible Na+ sensing system for the continuous monitoring of ionic components in biological fluids such as sweat and tears. GRAPHICAL ABSTRAC
%U https://www.tandfonline.com/doi/full/10.1080/14686996.2019.1656516