Detecting hydrogen sulfide by using transparent polymer with embedded CdSe/CdS quantum dots

Hydrogen sulfide (H2S) is a hazardous vapor commonly found in oil fields and industrial processes. In this paper, we first reported the fluorescence quenching of CdSe/CdS quantum dots (QDs) by hydrogen sulfide in dichloromethane. This response is highly specific because no response to other volatile organic vapors can be observed. Second, we embedded QDs in films of poly(dimethylsiloxane) (PDMS), a transparent and gas-permeable polymer, for detecting low level of hydrogen sulfide. After exposing the film to 10 ppm of hydrogen sulfide, the film loses its fluorescence within 1 min. However, the fluorescence recovers completely after the film is left in the open air for 2 h. Compared with other types of hydrogen sulfide sensors, the film sensor with embedded QDs is more portable, easy-to-operate and has low-cost.