Toward non-enzymatic glucose sensing based on organic electronics: organic field-effect transistors with multifunctionalized extended-gate electrodes

Accurate glucose analysis has been a major research focus for the past five decades since the pioneering development of enzymatic glucose sensing, driven by the global demand for rapid and reliable diagnostics. In contrast to well-established enzymatic glucose sensors, the development of chemical sensors based on supramolecular receptors remains a developing area. Among the supramolecular receptors for glucose, phenylboronic acid (PBA) derivatives provide unique functions, such as the formation of boronate esters with glucose and their reversibility. In this study, we focus on organic field-effect transistors (OFETs) combined with PBA derivatives as chemical sensors. Although the beneficial properties of OFETs have been explored for physical sensor applications in organic electronics, the instability of organic devices remains a major limitation for chemical sensing applications. To address this issue, an extended-gate structure was employed as the OFET-based chemical sensor configuration. In this sensor design, an extended-gate electrode functionalized with a PBA derivative self-assembled monolayer was connected to the gate electrode of the OFET, enabling glucose detection via boronate ester formation at the aqueous-sensing electrode interface. In this mini-review, we introduce strategies for establishing non-enzymatic glucose sensors using OFETs with multifunctionalized extended-gate electrodes. Notably, selective glucose detection in human blood plasma has been demonstrated by combining a two-dimensional material that suppresses the physical adsorption of endogenous proteins onto an extended-gate electrode. Finally, an approach that integrates a microfluidic chamber into an extended-gate-based OFET device is introduced to highlight the inherent reversibility of the PBA derivative.