Solution processed low power organic field-effect transistor bio-chemical sensor of high transconductance efficiency

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(Vth),good-enough bias-stress stability,and mechanical durability are shown to be the key prerequisites for realizing OFET bio-sensors of high transconductance efficiency(gm/ID)for large SNR.Combining a low trap-density channel and a high-k/low-k gate dielectric layer,low-temperature(<100℃)solution-processed flexible OFETs can meet the performance requirements to maximize the gm/ID.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).