A fluorescent probe for the monitoring of H 2 S levels in living cells and organisms is highly desirable. In this regard, nearinfrared (NIR) fluorescent probes have emerged as a promising tool. NIR-I and NIR-II probes have many significant advantages; for instance, NIR light penetrates deeper into tissue than light at visible wavelengths, and it causes less photodamage during biosample analysis and less autofluorescence, enabling higher signal-to-background ratios. Therefore, it is expected that fluorescent probes having emission in the NIR region are more suitable for in vivo imaging. Consequently, a considerable increase in reports of new H 2 Sresponsive NIR fluorescent probes appeared in the literature. This review highlights the advances made in developing new NIR fluorescent probes aimed at the sensitive and selective detection of H 2 S in biological samples. Their applications in real-time monitoring of H 2 S in cells and in vivo for bioimaging of living cells/animals are emphasized. The selection of suitable dyes for designing NIR fluorescent probes, along with the principles and mechanisms involved for the sensing of H 2 S in the NIR region, are described. The discussions are focused on small-molecule and nanomaterialsbased NIR probes.

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The simple off-the-shelf chemical 6,7-dihydroxycoumarin (1) based copper complex (1·Cu 2+ ) has been used for the selective detection of toxic cyanide in aqueous medium. The DFT calculation confirms the binding behavior between 1 and Cu2+ (2:1) and the red shift in the UV–vis spectrum with copper ion was confirmed by the decrease in energy between HOMO–LUMO band gaps. The cyanide sensing in water was confirmed by both absorption and emission spectral studies. Cyanide ion showed 13-fold increments in fluorescent intensity in emission spectrum via displacement of copper from 1·Cu 2+ . The limit of detection of CN– in water is 5.77 μM; 1·Cu 2+ also applicable for the detection of cyanide in fresh mouse serum with detection limit of 14.4 μM. The cell images showed that 1·Cu 2+ could be used to detect intracellular CN–.

Green and sustainable energy production through renewable sources is enormously an exciting field of research. Herein, we report A-site lanthanum doped oxygen excess ruthenate (predominantly Ru5+-ions) double perovskite system, CaLaScRuO6+δ...

Copper complex based on a new class of fluorescence OFF-ON sensor 1.Cu has been reported for the detection of trace amounts of water in various organic solvents such as CHOH, THF, CHCN, and acetone by means of fluorescence emission intensity. The probe is highly responsive to water in THF (DL = 0.003 wt %). The dissociation of copper from probe 1.Cu in the presence of water is responsible for the fluorescence change and it was confirmed by electrospray ionization-mass spectrometry (ESI-MS), proton nuclear magnetic resonance (H-NMR), and fluorescence lifetime studies. Real application of the probe was successfully applied for the detection of moisture content in commercial products such as salt, sugar, wheat, and washing powder.