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

Abstract

Titanium carbide quantum dots (Ti₃C₂ QDs) derived from two-dimensional (2D) Ti₃C₂T_<i>x</i> (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 <i>o</i>-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.