Bovine serum albumin template synthesis of fluorescent gold nanoclusters for nitric oxide detection in vitro

Bovine serum albumin (BSA) stabilised gold nanoclusters (Au NCs) were prepared and used for nitric oxide (NO) detection in vitro. The prepared BSA-Au NCs with an average diameter of 1.5 nm emitted strong red photoluminescence (PL), accompanied with the maximum emission peak at 640 nm. Furthermore, the BSA-Au NCs were developed as a PL probe for NO detection in vitro. Owing to the damage of BSA-Au NCs structure caused by the interaction between NO and BSA, the PL intensity of BSA-Au NCs regularly reduced with the increase in NO concentration [NO]. There is a proportional relationship between the PL intensity of BSA-Au NCs and the [NO] (0.05-0.35 mM), together with a detection limit of 0.017 mM. Experimental results confirmed high selectivity and sensitivity of the NO probe over other reactive oxygen and nitrogen species, and presented excellent detection capacity in aqueous model samples.