Novel visible-light-responsive photoelectrochemical sensor of 2,4-dichlorophenoxyacetic acid using molecularly imprinted polymer/BiOI nanoflake arrays

•The first smart integration of BiOINFs with molecularly imprinted Au nanoparticles–polypyrrole•MIP AuNPs–PPy not only as the recognition unit, but also with strong synergistic effects on the enhanced photocurrent•A highly sensitive and selective PEC sensing strategy developed for 2,4-D detection

A novel and highly sensitive visible-light photoelectrochemical (PEC) sensor for the detection of 2,4-D has been developed using a nanocomposite of molecularly imprinted gold nanoparticles-polypyrrole polymer (MIP) modified BiOI nanoflake arrays (BiOINFs) as a photoactive electrode (labeled as MIP@BiOINFs). Our results demonstrate that the smart combination of BiOINFs with MIP offers a high-performance photoactive sensing platform. It features the intrinsically excellent visible-light responsive properties of BiOI and prominent recognition ability from MIP. The designed MIP@BiOINF composite dramatically facilitates the PEC determination of 2,4-D. The detection limit for 2,4-D is found to be as low as about 0.04 ng mL− 1 (S/N = 3). Moreover, the resulting sensor could be used to detect 2,4-D in spiked soil samples.

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