In this study, rapid-detection iodide ion sensors based on sol-gel indium-gallium-zinc-oxide electrolyte gated thin-film transistors (IGZO-EGTFTs) have been examined. With a high electrical-double-layer capacitance (6.2 μF/cm2) at the interface between IGZO channel and physiological fluid (i.e., phosphate-buffered saline and artificial urine solution), the EGTFTs can be operated under 0.5 V with a high ON and OFF state current ratio above 108, and transconductance value of 1.14 mS. In addition to excellent electrical characteristics, the novel electrochemical reaction of IGZO-EGTFTs enables high selectivity and linear response over a wide detection range of iodide ions concentration (from 1 to 104 μM), the limit of detection as low as 1 μM, and response time below 0.1 s. The mechanism of iodide ions detection of IGZO-EGTFT was investigated based on electrochemical impedance spectroscopy analysis. We expect that IGZO-EGTFTs will contribute to the development of point-of-care rapid and reusable ion-sensors for human urine and serum.
This research was supported by the new faculty research fund of Ajou University and Korea Electric Power Corporation (Grant number R21XO01-20 ) and a research grant ( NRF-2020R1F1A1073564 and NRF-2021R1A4A1033155 ) from the National Research Foundation (NRF) funded by the Korea Ministry of Science and ICT . This work was supported by the Ministry of Food and Drug Safety (Program No 21153MFDS431 ). This research was also supported by Bio-convergence Technology Education Program through the Korea Institute for Advancement Technology(KIAT) funded by the Ministry of Trade, Industry and Energy (No. P0017805 ).
