Disposable photoelectrochemical sensing strip for highly sensitive determination of perfluorooctane sulfonyl fluoride on functionalized screen-printed carbon electrode

Owing to the lack of chromophores and ionizable functional groups, it is a significant challenge to determine perfluorooctane sulfonyl fluoride (PFOSF) by traditional high-performance liquid chromatography or liquid chromatography/mass spectrometry, especially at a low concentration. In this work a unique photoelectrochemical (PEC) sensing strip has been developed for the first time for the detection of PFOSF. The sensing strip is cost effective and disposable, whereby BiOI nanoflake arrays are fabricated on a home-made screen printed electrode through a facile one-step in-situ electrodeposition process, and then the molecule tags (i.e., molecularly imprinted polymers) for PFOSF are subsequently grafted on the surface. Benefitting from a three-dimensional interconnected framework, the as-fabricated sensing strip has a rapid response to the interfacial steric hindrance effect between the sensing platform and the target analyte of PFOSF. The elaborated PEC sensor exhibits a outstanding linear response to a concentration of PFOSF ranging from 0.05 to 500.0 ppb and a detection limit down to 0.01 ppb (S/N = 3) Furthermore, our low-cost and highly sensitive sensor has been further explored to detect PFOSF in real water samples, showing satisfactory results.