Titanium carbide MXenes combine with red-emitting carbon dots as a unique turn-on fluorescent nanosensor for label-free determination of glucose
Titanium carbide (Ti3C2), a new family of two-dimensional (2D) nanomaterials, have attracted extensive attention due to their unique structure and desirable physiochemical properties. Herein, we developed an effective and selective fluorescence turn on nanosensor for glucose based on Ti3C2 nanosheets combined with red-emitting carbon dots (RCDs). The fluorescence intensity of RCDs could be effectively quenched (>96%) by Ti3C2 nanosheets through inner-filter effect (IFE). In the presence of H2O2, the quenched fluorescence of the RCDs can remarkably recover due to the Ti3C2 nanosheets were oxidized into Ti(OH)4 by H2O2. Based on H2O2 generated from oxidation of catalyzed by glucose oxidase, the nanosensor can also be exploited for monitoring glucose. Under the optimal conditions, a linear relationship between the increased fluorescence intensity of RCDs and the concentration of glucose was established in the range from 0.1 to 20 mM. The detection limit was 50 µM (S/N = 3). The proposed nanosensor also represented excellent selectivity for glucose analysis in biological fluids samples, providing a valuable platform for glucose sensing in clinic diagnostics.