A highly sensitive photoelectrochemical detection of perfluorooctanic acid with molecularly imprined polymer-functionalized nanoarchitectured hybrid of AgI–BiOI composite

A rapid and ultrasensitive signal-off photoelectrochemical sensor has been developed under visible-light irradiation, for the detection of perfluorooctanoic acid (PFOA), especially low level PFOA present in environment, whereby a novel nanostructured probe made of molecularly imprinted polymer (MIP) modified AgI nanoparticles-BiOI nanoflake arrays (AgI-BiOINFs) is designed as the photoactive electrode (denoted as MIP@AgI-BiOINFs). Here, the unique nanoarchitectured hybrid of AgI-BiOINFs was first in situ synthesized via a facile successive ionic layer adsorption and reaction (SILAR) approach and then employed as a matrix to graft the recognition element of MIP. Such a newly designed PEC sensor exhibits high sensitivity and selectivity for the determination of PFOA. The PEC analysis is highly linear over the PFOA concentration ranging from 0.02 to 1000.0 ppb with a detection limit of 0.01 ppb (S/N=3). This value obtained by using the facile PEC sensor is comparable to the results obtained by using well-established liquid chromatography-tandem mass spectrometry (LC-MS/MS). Toward practical applications, this low-cost and sensitive assay was successfully applied to measure PFOA in real water samples.