NIR-II Fluorescence/Photoacoustic Dual Ratiometric Probes with Unique Recognition Site for Quantitatively Visualizing HS in Vivo.

Hydrogen persulfide (HS) plays a significant role in redox biology and signal transduction; therefore, quantitative visualization of HS in the deep tissue of living organisms is essential for obtaining reliable information about relevant pathophysiological processes directly. However, currently reported HS probes are unsuitable for this purpose because of their poor selectivity for many polysulfide species or their short wavelength, which hinders precise imaging in deep tissues. Herein, for the first time, we report a unique HS-mediated dithiole formation reaction.