Cu Nanoparticles/N-Doped Ti<sub>3</sub>C<sub>2</sub>T<sub><i>x</i></sub>-Based Fluorescence Sensor for Detecting Ascorbic Acid
Juan Huang, Chenyang Shen, Hongfei Gu, Guo Wang, Peng Zhou, Xinyu Liu, Kedi Yu, Yuanlong Qin, Kejia Zhou, Jiayue Zhang, Zhengbo Chen
Abstract
Although compared with natural enzymes and traditional artificial enzymes, oxidase mimetic nanoenzymes have superior performance; the number of specific biomolecules as the substrate is minimal, especially for ascorbic acid (AA) oxidase nanoenzymes. Herein, Cu nanoparticles/N-doped Ti 3 C 2 T x (Cu NPs/N–Ti 3 C 2 T x ), containing copper mimicking the active sites of natural AA oxidase, exhibit specific AA oxidase-like catalytic activity. Dehydroascorbic acid (DHAA) obtained from the oxidation of AA can react with o-phenylenediamine (OPD) to produce fluorescent 3-(1,2-dihydrox-yethyl) furo[3,4- b ]quinoxaline-1-one (DFQ). Thus, a fluorescence AA sensor is established based on the AA oxidase mimetic activity of Cu NPs/N–Ti 3 C 2 T x . Remarkably, an excellent linear range of 5–150 μM for the fluorescence method with a low detection limit of 0.437 μM could guarantee the sensitive detection of AA. In addition, the synthesized Cu NPs/N–Ti 3 C 2 T x can induce the generation of reactive oxygen species by accelerating the oxidation of AA, thereby effectively inhibiting the proliferation of cancer cells.