Harnessing Thermoelectric-Mediated Photoelectrochemical System to Address Sensitive Dopamine Detection via APE1-Amplified Triple-Helix Switching

Realizing sensitive biomolecular-to-electrical signal transduction necessitated addressing the insufficient photon utilization and low photo-to-electric conversion efficiency of current photoelectrochemical (PEC) sensors. Herein, we presented a facile sensing concept by harnessing thermoelectric-mediated PEC system to achieve sensitive detection of dopamine (DA) through APE1-amplified triple-helix switching. In this integrated design, an internal electric field arising from the BiOI/CdIn 2 S 4 p – n heterojunction was established for interfacial charge separation. Concurrently, leveraging the intrinsic thermoelectric properties of Ag 2 S, a thermoelectric field was generated under the photo-induced temperature gradient, which offered an additional driving force for charge separation. The dual-electric-field driving forces, assisted by APE1-participated signal amplification, significantly enhanced the sensitivity of the PEC sensing platform. This enabled precise, concentration-dependent signal transduction by converting molecular interactions into electrical outputs, achieving a low detection limit of 0.04 nM (3σ/N), excellent linearity, and outstanding specificity. This work displayed a thermoelectric-mediated PEC strategy that bridged energy conversion and molecular bioanalysis, opening a promising avenue toward intelligent, energy-efficient platforms for next-generation neurochemical diagnostics.