A turn-on fluorescent nanosensor for H2S detection and imaging in inflammatory cells and mice.

ABSTRACT

Hydrogen sulfide (H2S) is an endogenously generated gaseous signaling molecule and is known to be involved in the occurrence and development of inflammation. To better understand its physiological and pathological process of inflammation, reliable tools for H2S detection in living inflammatory models are desired. Although a number of fluorescent sensors have been reported for H2S detection and imaging, water-soluble and biocompatibility nanosensors are more useful for imaging in vivo. Herein, we developed a novel biological imaging nanosensor, XNP1, for inflammation-targeted imaging of H2S. XNP1 was obtained by self-assembly of amphiphilic XNP1, which was constructed by the condensation reaction of the hydrophobic, H2S response and deep red-emitting fluorophore with hydrophilic biopolymer glycol chitosan (GC). Without H2S, XNP1 showed very low background fluorescence, while a significant enhancement in the fluorescence intensity of XNP1 was observed in the presence of H2S, resulting in a high sensitivity toward H2S in aqueous solution with a practical detection limit as low as 32.3 nM, which could be meet the detection of H2S in vivo. XNP1 also has a good linear response concentration range (0-1 µM) toward H2S with high selectivity over other competing species. These characteristics facilitate direct H2S detection of the complex living inflammatory cells and drug-induced inflammatory mice, demonstrating its practical application in biosystems.