A hydrogen sulfide and tyrosinase responsive dual-locked fluorophore for selective imaging of melanoma cells

A resorufin-based dual-locked fluorescent probe (RHT) was introduced to image melanoma cells selectively. RHT was shown to function as an AND molecular logic gate as it emitted a signal only in the presence of both hydrogen sulfide (H₂S) and tyrosinase (Tyr), which are known to be overexpressed in melanoma cells. In vitro cell culture studies revealed that RHT can be activated with endogenous H₂S and Tyr and allows selective imaging of B16-F10 cancer cells under confocal microscopy. RHT marks the first ever example of a fluorescent probe that is sequentially activated by H₂S and Tyr.