Fluorescence sensor array for biothiols detection and disease identification based on CoOOH nanoflakes triggered dual-color fluorescence system

Abstract

Biothiol analysis holds critical importance in disease diagnosis, whereas the highly similar structures of biothiols pose a major obstacle in their practical detection. Herein, a straightforward yet efficient CoOOH nanoflakes (CoOOH NFs)-triggered dual-color fluorescence sensor array has been developed for the discrimination of biothiols. Owing to their high oxidase-like activity, CoOOH NFs efficiently catalyze the oxidation of fluorometric signal indicators, resulting in diverse fluorescence signals. However, the presence of biothiols induced structural degradation of CoOOH NFs via redox etching, thereby inhibiting the fluorescence reactions. Due to the differential reducing capacities of biothiols, the sensor array produced unique fluorescence response patterns, which were further analyzed using principal component analysis (PCA) and hierarchical cluster analysis (HCA). The results demonstrated that the sensor array could reliably discriminate three biothiols (glutathione (GSH), cysteine (Cys), and homocysteine (Hcy)) across a broad concentration range (0.5-100 μM), as well as their mixtures with varying molar ratios. Importantly, this strategy was successfully applied to distinguish cancer cells from normal cells and to analyze clinical serum samples, highlighting its potential for medical diagnostics.