A highly sensitive and specific luminescent MOF determines nitric oxide production and quantifies hydrogen sulfide-mediated inhibition of nitric oxide in living cells.

The synthesis of a novel carboxylate-type organic linker-based luminescent MOF (Zn(HL) (L)) (named PUC2) (HL = 2-aminoterephtalic acid, L = 1-(3-aminopropyl) imidazole) is reported by the solvothermal method and comprehensively characterized using single-crystal XRD, PXRD, FTIR, TGA, XPS, FESEM, HRTEM, and BET. PUC2 selectively reacts with nitric oxide (NO) with a detection limit of 0.08 µM, and a quenching constant (0.5 × 10 M) indicating a strong interaction with NO. PUC2 sensitivity remains unaffected by cellular proteins or biologically relevant metals (Cu/ Fe/Mg/ Na/K/Zn), RNS/ROS, or HS to score NO in living cells. Lastly, we used PUC2 to demonstrate that HS inhibition increases NO production by ~ 14-30% in various living cells while exogenous HS suppresses NO production, indicating that the modulation of cellular NO production by HS is rather generic and not restricted to a particular cell type. In conclusion, PUC2 can successfully detect NO production in living cells and environmental samples with considerable potential for its application in improving the understanding of the role of NO in biological samples and study the inter-relationship between NO and HS.