Visual detection of biological thiols based on lightening quantum dot–TiO2 composites

The quenched fluorescence of quantum dots (QDs) attached to TiO2 nanoparticles was selectively switched on by biothiols through ligand replacement, which makes it feasible for facilely sensing biothiols based on the fluorescence turn on mechanism. The present sensor exhibited excellent selectivity and high sensitivity. Furthermore, a novel fluorescent indicating paper was constructed by immobilizing the probe on filter paper to visually detect biothiols in which only a UV lamp was used.