A bioinspired ratiometric fluorescence probe based on cellulose nanocrystal-stabilized gold nanoclusters for live-cell and zebrafish imaging of highly reactive oxygen species

The detection of highly reactive oxygen species (hROS) is critical to both understanding disease etiology and optimizing therapeutic interventions. Here, a ratiometric fluorescent probe based on cellulose nanocrystal (CNC)-stabilized gold nanoclusters was constructed for hROS detection using CNCs as carriers and stabilizers of gold nanoclusters and o-phenylenediamine as an anti-interference internal standard for ROS. CNCs prepared from biocompatible biomass and with high carboxyl density and needle-shaped and rod-like structures were sufficient to address the easy aggregation and instability of gold nanoclusters. The as-prepared ratiometric fluorescent probe inspired by the chameleon changes colour when encountering environmental stimuli exhibited good stability, high sensitivity and selectivity, and was capable of long-term storage. Interestingly, in the pres-ence of hROS, the fluorescence of the probe changed from blue to yellow, revealing detection limits for ClO-, ONOO-, and & BULL;OH of 0.97 mu mol/L, 0.87 mu mol/L, and 0.79 mu mol/L, respectively. Subsequent application for direct fluorescence imaging of hROS in living cells and zebrafish demonstrated satisfactory sensitivity. These results suggested the efficacy of the CNC-stabilized gold nanoclusters for practical application in biological systems.

Automated summary

A ratiometric fluorescent probe based on CNC-stabilized gold nanoclusters was developed for the detection of hROS, showing good stability and high sensitivity, and demonstrated satisfactory fluorescence imaging of hROS in living cells and zebrafish.