Photoelectric Response of Glutathione Based on Electron Transfer Mechanism at the Interface of CdTe/MX (X=Te, Se, S, O) Nanoparticles

The important roles of glutathione (GSH) in maintaining the normal operation of biological systems and cellular functions have attracted great research attention. Considering the crucial role of GSH in biological processes, it is important to develop an affordable and sensitive fluorescent sensor for the identification of GSH. Herein, a series of CdTe/MX (M=Zn, Cd, Sb, Bi; X=Te, Se, S, O) nanoparticles were prepared by a liquid-phase method. Major efforts were focused on the fluorescence response of GSH at the CdTe/MX interface, such as the effect of electron transfer on the fluorescence response of GSH. The fluorescence response of GSH adsorbed on the CdTe/MX interface via its -SH group could be divided into two types: fluorescence enhancement and quenching. When the CdTe/MX nanoparticles formed conduction band alignment, the fluorescence response was enhanced, and the intensity increased 1.35–2 times. Moreover, valence band alignment resulted in fluorescence quenching of the CdTe/MX nanoparticles, and the intensity decreased by 18.13%–55.42%. Finally, the limit of detection for GSH was 1 μM in the determination range of 0.005–0.1 mM. Based on the above phenomena, it was very helpful to prepare a GSH fluorescent switch sensor and understand its function in biological systems.