Turn-On Fluorescence Detection of Glutathione Based on o-Phthaldialdehyde-Assisted SiO2 Particles

Abstract

We report about the fluorometric method for the determination of glutathione (GSH) in dietary supplements. The fluorometric assay is based on the use of functionalized silica particles (SiO2-SH) in combination with o-phthaldialdehyde (OPA). The fluorescence excitation and emission wavelengths were located at 340 nm and 430 nm. The relative fluorescence intensity was linear in the concentration range between 1.0 × 10−7 mol/L and 1.0 × 10−5 mol/L (M) with the detection limit of 3.4 × 10−7 M. The fluorescent silica particle-based sensor was successfully employed for the determination of GSH in dietary supplements with excellent recoveries. The proposed sensor may pave a new way for fluorescence sensing of other substances in food samples.