A ruthenium nitrosyl complex-based highly selective colorimetric sensor for biological H 2 S and H 2 S-NO cross-talk regulated release of NO.

A ruthenium nitrosyl complex (1·NO) and 1·NO incorporated phospholipid-based liposomes (Lip-1·NO) were reported for highly selective colorimetric detection of H 2 S. The probe 1·NO "cross-talks" with H 2 S and releases nitric oxide (NO) in the process. The detection limit for H 2 S was found to be 0.31 μM and 0.45 μM in the cases of 1·NO and Lip-1·NO, respectively. The DAF-FM DA assay has been performed to confirm the H 2 S-induced NO release from 1·NO and Lip-1·NO. The sensing of H 2 S was also verified by ESI-MS and FT-IR spectroscopy. It was also observed that external stimuli, H 2 S and light worked in an almost similar way to release NO as observed by UV-Vis spectroscopy. A molecular logic gate operation "OR" was applied to the probe 1·NO in combination with inputs 'light' and 'H 2 S' to give the output 'NO release'. Hence, the probe 1·NO performs the dual work of sensing H 2 S with a colorimetric response, releasing NO upon cross-talk between NO and H 2 S.