Cu Nanoparticles/N-Doped Ti3C2Tx-Based Fluorescence Sensor for Detecting Ascorbic Acid

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 Ti3C2Tx (Cu NPs/N–Ti3C2Tx), 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–Ti3C2Tx. 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–Ti3C2Tx can induce the generation of reactive oxygen species by accelerating the oxidation of AA, thereby effectively inhibiting the proliferation of cancer cells.