Dual-Emission Reverse Change Ratio Photoluminescence Sensor Based on a Probe of Nitrogen-Doped Ti3C2 Quantum Dots@DAP to Detect H2O2 and Xanthine

Titanium carbide quantum dots (Ti3C2 QDs) derived from two-dimensional (2D) Ti3C2Tx (MXene) are the rising-star material recently. Herein, nitrogen-doped Ti3C2 QDs (N-Ti3C2 QDs) were synthesized via a solvothermal method. The obtained N-Ti3C2 QDs exhibited excitation-dependent photoluminescence, antiphotobleaching, and dispersion stability. Furthermore, by combining the N-Ti3C2 QDs and DAP (2,3-diaminophenazine, the oxidative product of o-phenylenediamine) as a composite nanoprobe (N-Ti3C2 QDs@DAP), we developed a dual-emission reverse change ratiometric sensor to quantitatively monitor H2O2 based on photoinduced electron-transfer effects, where N-Ti3C2 QDs acted as the donor and DAP as the acceptor. On the basis of the xanthine converting into H2O2 through the catalysis of xanthine oxidase, the N-Ti3C2 QDs@DAP nanoprobe was also exploited for xanthine sensing. As a result, the proposed assay was demonstrated to be highly sensitive for H2O2 and xanthine with detection limits of 0.57 and 0.34 μM, respectively. In a word, we have investigated the application of N-Ti3C2 QDs in H2O2 and xanthine sensing and opened a new and exciting avenue for the N-Ti3C2 QDs in biosensing.