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).

开发有机场效应晶体管 (OFET) 生物传感器可定制检测许多疾病的生物标志物，将为生物学研究和临床诊断提供低成本且方便的工具。在这项工作中，导出了用于生物传感器的 OFET 换能器的设计原则，以将信噪比 ( SNR ) 与设备性能参数联系起来。陡峭的亚阈值摆幅 ( SS )、合适的阈值电压 ( Vth )、足够_好的偏置应力稳定性和机械耐久性是实现高跨导效率 ( g _m / I _D )的 OFET 生物传感器的关键先决条件对于大信噪比. 结合低陷阱密度沟道和高k /低k栅极介电层，低温 (<100 °C) 溶液处理的柔性 OFET 可以满足最大化g _m / I _D的性能要求。进一步实施了扩展的栅极结构 OFET 生物传感器，用于 miR-21 的无标记检测，在低工作电压 (<1 V) 下实现了低于 10 pM 的检测限和高选择性。