Efficient Turn-On Fluorescent Sensor Based on Fluorescent Resonance Energy Transfer between 1,3,6,8-Tetra(4-pyridyl)pyrene and Gold Nanoparticles for Glutathione Detection

A fluorescent probe based on fluorescent resonance energy transfer (FRET) between the organic fluorophore 1,3,6,8-tetra(4-pyridyl) pyrene (TTPY) and gold nanoparticles (AuNPs) was designed for detecting glutathione (GSH) in foods. TTPY, synthesized via a Suzuki–Miyaura coupling reaction, exhibited excellent fluorescence properties with a maximum emission wavelength of 496 nm. Acting as an energy donor, TTPY transfers energy to AuNPs via FRET, resulting in fluorescence quenching of TTPY. In the presence of GSH, TTPY was displaced from the AuNP surface, restoring the fluorescence of the TTPY chromophore. The developed sensor demonstrated excellent water solubility and selectivity and a low detection limit (54 nM). Moreover, the proposed method was successfully applied for the determination of GSH in food samples, demonstrating its potential for food antioxidant analysis.