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(H2L) (L-1)) (named PUC2) (H2L = 2-aminoterephtalic acid, L-1 = 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)-N-square) with a detection limit of 0.08 mu M, and a quenching constant (0.5 x 10(4) M-1) indicating a strong interaction with (NO)-N-square. PUC2 sensitivity remains unaffected by cellular proteins or biologically relevant metals (Cu2+/ Fe3+/Mg2+/ Na+/K+/Zn2+), RNS/ROS, or H2S to score (NO)-N-square in living cells. Lastly, we used PUC2 to demonstrate that H2S inhibition increases (NO)-N-square production by similar to 14-30% in various living cells while exogenous H2S suppresses (NO)-N-square production, indicating that the modulation of cellular (NO)-N-square production by H2S is rather generic and not restricted to a particular cell type. In conclusion, PUC2 can successfully detect (NO)-N-square production in living cells and environmental samples with considerable potential for its application in improving the understanding of the role of (NO)-N-square in biological samples and study the inter-relationship between (NO)-N-square and H2S.