Sensitive Fluorescent Sensor for Hydrogen Sulfide in Rat Brain Microdialysis via CsPbBr 3 Quantum Dots

The instability and insolubility of perovskite quantum dots in aqueous solution prohibit applications in polar solvents. As a highly toxic gas pollutant and also an endogenous gaseous signaling molecule existing in a variety of physiological processes, hydrogen sulfide (H 2 S), with high selectivity and high specificity, detection is of great significance. In this study, a simple device has been designed to separate H 2 S from aqueous solution and CsPbBr 3 quantum dots (CsPbBr 3 QDs) have been used as the detection probe to develop a novel fluorescent sensor for rapid H 2 S detection. The addition of hydrogen sulfide to the phosphoric acid solution results in the escape of H 2 S from the aqueous sample and hence it passing into the n -hexane solution containing CsPbBr 3 QDs, resulting in the quenching of the fluorescence of CsPbBr 3 QDs. The fluorescence intensity of the system has a linear relationship with the concentration of H 2 S in the range of 0–100 μM with the detection limit of 0.18 μM. The proposed system has been applied to detection of H 2 S in rat brain microdialysate with satisfying results. The potential mechanism regarding the quenching of fluorescence from CsPbBr 3 QDs by H 2 S has been studied as well.