Visible-light-driven photoelectrochemical sensing platform based on BiOI nanoflowers/TiO2 nanotubes for detection of atrazine in environmental samples

In this work, a visible-light-driven photoelectrochemical (PEC) sensing platform was developed based on BiOI nanoflowers/TiO2 nanotubes (BiOI NFs/TiO2 NTs) for detection of atrazine (ATZ). The BiOI NFs/TiO2 NTs p–n heterojunctions synthesized by decorating BiOI NFs on TiO2 NTs via simple hydrothermal approach exhibit strong visible-light absorption ability, high photocurrent response and PEC activity. Thus BiOI NFs/TiO2 NTs heterostructures were first explored to act as the photoelectrode for the immobilization of the anti-ATZ aptamer to develop a PEC sensing platform. The design PEC aptasensing platform exhibits prominent analytical performance for determination of ATZ with a low detection limit of 0.5 pM under visible-light irradiation, and displays good selectivity for ATZ in the control experiments. The superior behavior of the sensing platform could be ascribed to the design of the appropriate sensing material with tubular microstructure, excellent PEC response of the photoelectrode, and the large loading amount of aptamer. Meanwhile, the PEC sensing platform was used to determine ATZ in environmental samples and a satisfied result was obtained.