BSA-modified gold nanoclusters for sensing of folic acid

Gold nanoclusters have found increasing interests for fabricating of novel sensors and biosensors. This paper presents a simple, rapid and novel method for determination of folic acid (FA) based on the quenching of the fluorescence of BSA-modified gold nanoclusters. By analysis of the fluorescence and absorbance spectra of the gold nanoclusters in the presence and absence of FA, the probable mechanism of florescence quenching of BSA-AuNCs by FA was investigated. In the physiological pH of 7.4, the fluorescence quenching was fitted to Stern-Volmer equation with a linear response in the concentration range of 120.0 ng mL−1 to 33.12 μg mL−1 and the detection limit of 18.3 ng mL−1. Furthermore, the feasibility of the proposed method for determination of the contents of folic acid in pharmaceutical tablets was demonstrated. The results were agreed with the claimed values.