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

Abstract

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 presence of hROS, the fluorescence of the probe changed from blue to yellow, revealing detection limits for ClO−, ONOO−, and ∙OH of 0.97 μmol/L, 0.87 μmol/L, and 0.79 μmol/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.