Turn-on fluorescent probe for Cd2+ detection by gold nanoclusters/graphene oxide nanocomplex

This work reported the fabrication of bovine serum albumin stabilised gold nanoclusters (BSA-Au NCs)–graphene oxide nanocomplex (BSA-Au NCs-GO) as a ‘turn-on’ fluorescent probe for the detection of Cd 2+ . The prepared BSA-Au NCs showed an intense red fluorescence, and the fluorescence of BSA-Au NCs was reduced significantly by graphene oxide due to its excellent quenching properties. However, in the presence of 65 µmol l −1 Cd 2+ , the fluorescence intensity recovered to 82.5% of the intensity of BSA-Au NCs, and the fluorescence intensity increased 1.3-fold relative to the BSA-Au NCs-GO nanocomplex. This proposed probe expands the application of BSA-Au NCs, which can be used as a reversible fluorescence nanoswitch for inexpensive, label free and simple detection of Cd 2+ in the aqueous samples.