The result demonstrated that the adsorption of H2S on the surface of QDs is fully reversible.
In fact, the experiment can be repeated several times without losing any fluorescence intensity as shown in Fig. 5.
The observation suggests that the QDs embedded in the PDMS film can absorb H2S vapor reversibly.
We note that this is different from QDs in dichloromethane, which cannot regain their fluorescence even after purging with nitrogen for 1min.