Organic electrochemical transistors for metabolite sensing across the transition from in vitro to in vivo

Organic electrochemical transistors (OECTs) offer unparalleled signal amplification and biocompatibility for biomolecular sensing. This review systematically explores OECT principles, sensing mechanisms, and architectures, focusing on advancements in metabolite detection. We highlight how innovations in polymer materials and gate functionalization enhance in vitro detection performance. Crucially, we evaluate the emerging transition toward in vivo applications, addressing the technological hurdles of signal fidelity and tissue-device interfaces in complex biological systems.