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 mu g 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. (C) 2014 Elsevier B.V. All rights reserved.