Solution processed low power organic field-effect transistor bio-chemical sensor of high transconductance efficiency
Wei Tang, Ying Fu, Yukun Huang, Yuanzhe Li, Yawen Song, Xin Xi, Yude Yu, Yuezeng Su, Feng Yan, Xiaojun Guo
Abstract
Abstract Developing organic field-effect transistor (OFET) biosensors for customizable detection of biomarkers for many diseases would provide a low-cost and convenient tool for both biological studies and clinical diagnosis. In this work, design principles of the OFET transducer for biosensors were derived to relate the signal-to-noise ratio ( SNR ) to the device-performance parameters. Steep subthreshold swing ( SS ), proper threshold voltage ( V th ), good-enough bias-stress stability, and mechanical durability are shown to be the key prerequisites for realizing OFET bio-sensors of high transconductance efficiency ( g m / I D ) for large SNR . Combining a low trap-density channel and a high- k /low- k gate dielectric layer, low-temperature (<100 °C) solution-processed flexible OFETs can meet the performance requirements to maximize the g m / I D . An extended gate-structure OFET biosensor was further implemented for label-free detection of miR-21, achieving a detection limit below 10 pM with high selectivity at a low operation voltage (<1 V).