Construction of xylan-based high-biocompatibility fluorescent probe for viscosity detection in live organisms

Viscosity is an indispensable micro-environmental parameter that affects the diffusion of matter and molecular activity in biological systems. Abnormal changes in viscosity levels are strongly associated with various human diseases, such as thrombosis, Alzheimer's disease, and the formation of malignant tumors. This paper reports a highly biocompatible xylan-based viscosity fluorescent probe (Xyl-V) for cell-level viscosity measurement. Xyl-V is constructed using non-toxic and biodegradable xylan (Xyl) in plant resources, combined with mitochondrial targeting and a near-infrared emission luminescent group. Under viscous conditions, the fluorescence of Xyl-V at 580 nm and 820 nm is very sensitive to viscosity changes, and the fluorescence intensity increases by 16 and 32 times with the increase in viscosity level, respectively. As the first xylan-based probe for viscosity detection, it has excellent selectivity, low toxicity, high biocompatibility, and superior detection performance in the living cell environment.