Harnessing the Synergy of Ti ₃ C ₂ T <i> _x </i> /CuO Nanocomposites and Charge Transport of FET-Based Transducers for High-Performance Sensing

The rapid evolution of organic field-effect transistors (OFETs) as versatile sensing platforms has primarily focused on architecture and probe engineering, often overlooking the intrinsic role of charge carrier mobility (μ) in transduction performance. Herein, we present a systematic study that correlates μ of polymer-based OFETs with critical sensing parameters using an extended-gate (EG) configuration for nonenzymatic glucose detection. To the best of our knowledge, this is the first EG-OFET study to quantitatively map how μ governs sensitivity, LOD/LOQ, and response time under an identical sensing architecture and measurement protocol. A novel nanocomposite, Ti₃C₂T<i>_x</i>/CuO, was synthesized as the active sensing interface and integrated with OFETs fabricated from conjugated polymers (CPs) with varying μ, such as NR-P3HT, RR-P3HT, and DPP-TTT. Uniaxially aligned, edge-on oriented, and uniform thin films of these CPs used as active semiconducting elements of the OFETs were fabricated by the unidirectional floating film transfer method. We demonstrate that increasing μ significantly enhances sensitivity, lowers detection limits, and improves response time. This is supported through a high-μ DPP-TTT-based, OFET achieving a remarkable sensitivity of 0.52 V mM^-1 cm^-2 and a detection limit of 0.56 mM, surpassing even standard electrochemical platforms. By codesigning a catalytic Ti₃C₂T<i>_x</i>/CuO extended-gate interface with mobility-engineered polymer transducers, we demonstrate a clear materials-transducer synergy in which higher μ enables stronger and faster electrical transduction of interfacial potential changes. These findings establish a μ-guided design rule for engineering next-generation EG-OFET sensors with improved sensitivity and speed. Thus, these findings bridge the gap between fundamental charge transport and applied sensing performance, establishing a new paradigm for engineering next-generation OFET sensors.