Interaction of ZnS nanoparticles with flavins and glucose oxidase: A fluorimetric investigation

► Unique interaction specificity of ZnS nanoparticles with flavins has been explored. ► Unlike protein-bound flavin, fluorescence of free flavins was quenched by ZnS nanoparticles. ► FMN and FAD show quenching to different extents under analogous conditions. ► Fluorescence lifetime measurement confirmed the quenching to be static in nature. ► This study is useful for probing riboflavin in biological systems.