Dual-Photoelectrode Fuel Cell Based Self-Powered Sensor for a Picomole Level Pollutant: Using an In Situ Molecularly Imprinted p-Type Organic Photocathode.

Abstract

Developing a dual-photoelectrode fuel cell based self-powered sensor (DPFC-SPS) with an ideal signal output capability and high sensitivity performance for the detection of environmental pollutant atrazine (ATZ) has an important value. In this work, the in situ molecularly imprinting functionalized p-type organic semiconductor polyterthiophene (MI-pTTh) is used as a photocathode to construct a DPFC-SPS toward the typical environmental pollutant ATZ for the first time. Due to its excellent photoactivity, higher stability, and superior oxygen reduction reaction activity, pTTh serves as the photocathode material for constructing a self-powered sensing platform with a stable signal output and high photoelectric activity. Based on the sensitive light-triggered large self-bias of the DPFC-SPS, the open circuit potential (EOCV) of the device reaches 1.21 V and the maximum power density (Pmax) reaches 121.5 μW·cm-2, which is much higher than most reported PFC-SPSs. Simultaneously, in situ molecularly imprinted (MI) functionization of pTTh can further endow it with specific recognition ability, helping the constructed SPS achieve high sensitivity, selectivity, and effective recognition of the important environmental pollutants ATZ in complex systems. It exhibits a broad linear relationship from 0.002 to 100 nM and a low detection limit (estimated by S/N > 3) of 0.21 pM toward ATZ. The mechanism of the binding kinetics of the MI-pTTh with the target ATZ is further studied via in situ infrared spectroscopy. This work provides theoretical guidance for sensing strategies using dual-photoelectrode devices and offers a rational device design for cost-effective electricity generation from renewable resources.