Synthesis of Fluorescent Gold Nanoclusters Directed by Bovine Serum Albumin and Application for Nitrite Detection

In the present work, gold nanocluster (GNC) induced by bovine serum albumin (BSA) was synthesized as a novel fluorescence probe to detect nitrite (NO2−) sensitively and selectively. The fluorescence of GNC was found to be quenched effectively by NO2−. Under the optimum conditions, it was found that the change of fluorescence intensity was proportional with the concentration of NO2− in the linear range of 0.1–50 μM (R = 0.9990), with a detection limit (S/N = 3) of 30 nM. The absorption spectroscopy, circular dichroism (CD), and X-ray photoelectron spectroscopy (XPS) studies were employed to discuss the quenching mechanism. In addition, the present approach was successfully applied in real water samples.