A stable and sensitive Au metal organic frameworks resonance Rayleigh scattering nanoprobe for detection of SO32– in food based on fuchsin addition reaction

Abstract

A stable Au metal organic frameworks (AuMOF) nanosol was prepared. It was characterized by electron microscopy and molecular spectral techniques. In pH 6.8 PBS buffer solution, AuMOF nanoprobes exhibit a strong resonance Rayleigh scattering (RRS) peak at 330 nm. After basic fuchsin (BF) adsorbing on the surface of AuMOF, the RRS energy of the nanoprobe donor can be transferred to BF receptor, resulting in a decrease in the RRS intensity at 330 nm. Both sulfite and BF taken place an addition reaction to form a colorless product (SBF) that exhibit weak RRS energy transfer (RRS-ET) between AuMOF and SBF, resulting in the enhancement of the RRS peak. As the concentration of SO32–increases, the RRS peak is linearly enhanced. Thus, a new and sensitive RRS-ET method for the detection of SO32– (0.160–5.00 μmol/L) was developed accordingly using AuMOF as nanoprobes, with a detection limit of 0.0800 μmol/L. This new RRS method was applied to determination of SO32– in food and SO2 in air samples. The recoveries of food and air samples were 97.1–106% and 92.9–106%, and the relative standard deviation (RSD) was 2.10–4.80% and 2.10–4.50%, respectively.