A novel photoelectrochemical sensor based on molecularly imprinted polymer modified TiO2 nanotubes and its highly selective detection of 2,4-dichlorophenoxyacetic acid

As a putative endocrine disruptor that lacks electrochemical activity, 2,4-dichlorophenoxyacetic acid (2,4-D) was hard to be detected by direct electrochemistry technique. This study described a highly selective and sensitive 2,4-D photoelectrochemical sensor based on modified TiO2 nanotubes (TiO2 NTs) with a low detection limit of 10 nM (S/N = 3). For the first time, a polypyrrole-based molecularly imprinted polymer was used as recognition element in a photoelectrochemical sensor, which gave it the capability of high selectivity for 2,4-D determination in multicomponent water samples. Results indicated that 20-fold excess of other coexistent pesticides hardly caused any interference on the photocurrent of 2,4-D. The practical application of the sensor was also realized for the selective determination of 2,4-D in spiked samples. The study made a successful attempt in the development of highly selective and sensitive photoelectrochemical sensor for endocrine disruptors monitoring.

► A highly selective and sensitive 2, 4-D photoelectrochemical sensor was fabricated.
► Molecularly imprinted PPy remarkably improved the selectivity of the sensor.
► Sensitivity of the sensor was greatly enhanced by PPy with conjugation structure.
► Stable and repeatable photoelectrochemical analytical method was established.