Facile Fluorescent Differentiation of Aminophenol Isomers Based on Ce-Doped Carbon Dots

Establishing a facile distinction protocol for isomers is still imminently desired. However, the use of a fluorescent probe to differentiate between aminophenol isomers is rarely reported. Herein, we propose a novel fluorescent strategy, based on cerium-doped carbon dots (Ce-CDs), for the convenient differentiation and sensitive monitoring of aminophenol isomers. The Ce-CDs were synthesized through a facile hydrothermal approach using Dendrobium officinale and Ce(NH4)2(NO3)6 as raw materials; the Ce-CDs possessed sufficient stability and excellent peroxidase-like activity. The synthesized Ce-CDs can catalyze the H2O2-mediated oxidation of aminophenol isomers resulting in different fluorescence behaviors, which is convenient for distinction of the aminophenol isomers. Notably, the Ce-CD-based fluorescent sensor was highly selective and sensitive for determining o-aminophenol (OAP) and m-aminophenol (MAP) with a low detection limit of 0.033 μM, respectively. The fluorescent method was successfully applied to monitor the presence of MAP and OAP in real water samples, which illustrated its significant potential for application in other environmental assays.