Facile microwave-assisted synthesis of TiC MXene quantum dots for ratiometric fluorescence detection of hypochlorite.

A dual-channel "naked-eye" colorimetric and ratio fluorescent probe has been developed based on titanium carbide quantum dots for the detection of curcumin and hypochlorite (ClO). The fluorescence emission of TiC MXene quantum dots (TiC MQDs) is in the range 350-600 nm, and the maximum emission peak is at 430 nm that overlaps with the UV absorption of curcumin at 430 nm to a large extent. This facilitates the fluorescence resonance energy transfer (FRET) between TiC MQDs and curcumin. When ClO is added, the phenolic and methoxy groups of curcumin are oxidized to quinones, resulting in the restoration of the fluorescence of TiC MQD. In addition, the probe designed makes it easier to distinguish colors with the naked eye to detect curcumin and ClO. The linear detection range of curcumin was 0.05-10 μM, and the detection limit was 20 nM. The linear detection ranges of ClO are 25-150 μM and 150-275 μM, and the detection limit is 5 μM. This study is the first report on the determination of curcumin and ClO based on TiC MQDs by dual-channel "naked-eye" colorimetric and ratio fluorescence method.