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...