Colorimetric sensor based on 4-mercaptophenylboronic modified gold nanoparticles for rapid and selective detection of fluoride anion.

A highly selective and sensitive colorimetric sensor based on aggregation-induced color change of 4-mercaptophenylboronic modified gold nanoparticles was designed for the determination of fluoride anion. The 4-mercaptophenylboronic modified gold nanoparticles were synthesized by a simple one-pot reaction. The aggregation process occurred when interaction between fluoride anion and 4-mercaptophenylboronic on the surface of gold nanoparticles took place; as a result, fluoroborate anions were formed coupled with changes in the electronic properties of the AuNPs. The change can be measured by UV-Vis absorption spectra. The sensor shows good selectivity and sensitivity for fluoride anion. The linear range is 10.0-30.0 μM for fluoride and the detection limit of fluoride is 3.45 × 10-7 M according to IUPAC criteria (3σ rule). Furthermore, the sensor has been used for the detection of fluoride anion in tap water, ground water and human serum samples, the recovery can achieve 94.0%-103.3%, 94.7%-101.0% and 89.8-100.9%, respectively. The excellent performance of colorimetric sensor in the detection of the fluoride anion demonstrated the potential application in the detecting fluoride anion present in the complex environmental and biological samples.