Preparation and Sensing Study of <i>Houttuynia cordata</i>-Based Carbon Quantum Dots

This study used Houttuynia cordata as the precursor to prepare high fluorescence quantum yield carbon quantum dots (Hc-CQDs) by a simple hydrothermal method. The surface of the Hc-CQDs contained abundant functional groups, such as carboxyl, hydroxyl, and amino groups, which indicated the Hc-CQDs had good water solubility. On the basis of the excellent fluorescence characteristics of Hc-CQDs, a sensor was constructed to achieve high selectivity detection of Cr³⁺, and the detection limit of the Hc-CQDs was 49 μg/L. The sensor also exhibited strong anti-interference ability and excellent reproducibility, which was used for the determination of Cr³⁺ in environmental water samples, and its spiked recovery rate reached over 90%. Therefore, the Hc-CQDs had potential application in the analysis.