Silica Coated Perovskite Quantum Dots with Single-Particle Level for Dual-Mode and Smartphone-Assisted Detection of Glutathione

The sensitive detection of glutathione (GSH) level is of great significance to disease diagnosis. However, commonly used fluorometry method usually suffers from limited sensitivity, potential interferences and inefficient detection. In this work, a smartphone-assisted and perovskite-based sensing platform for dual-readout detection of GSH was developed: the silica coated perovskite quantum dots (PQD@SiO 2 ) with a single particle level and high fluorescence efficiency were employed as fluorophore, which greatly avoids aggregation-caused quenching effect caused by multi-particles embedded in one SiO 2 shell, and the manganese dioxide (MnO 2 ) nanosheets were used as quencher. With the addition of GSH, the fluorescence intensity of PQD@SiO 2 -MnO 2 composites gradually enhances, while the color of solution turns from dark brown to light yellow under sunlight, which enables the dual-signal (fluorescence and colorimetric) and reliable detection of GSH level. In addition, the introduction of smartphones integrated image recording and data processing, further promotes the simple, visualized, cost-effective and real-time determination of GSH. The synthesis of PQD@SiO 2 at a single particle level, as well as the strategies of dual-mode and smartphone-assisted detection, holds the promising prospect in biosensing and chemical sensing.