Chromium is a harmful contaminant showing mutagenicity and carcinogenicity. Therefore, detection of chromium requires the development of low-cost and high-sensitivity sensors. Herein, blue-fluorescent carbon quantum dots were synthesized by one-step hydrothermal method from alkali-soluble Poria cocos polysaccharide, which is green source, cheap and easy to obtain, and has no pharmacological activity due to low water solubility. These carbon quantum dots exhibit good fluorescence stability, water solubility, anti-interference and low cytotoxicity, and can be specifically combined with the detection of Cr(VI) to form a non-fluorescent complex that causes fluorescence quenching, so they can be used as a label-free nanosensor. High-sensitivity detection of Cr(VI) was achieved through internal filtering and static quenching effects. The fluorescence quenching degree of carbon dots fluorescent probe showed a good linear relationship with Cr(VI) concentration in the range of 1–100 μM. The linear equation was F₀/F = 0.9942 + 0.01472 [Cr(VI)] (R² = 0.9922), and the detection limit can be as low as 0.25 μM (S/N = 3), which has been successfully applied to Cr(VI) detection in actual water samples herein.

铬是一种有害污染物，具有致突变性和致癌性。因此，铬的检测需要开发低成本、高灵敏度的传感器。本文以碱溶性茯苓为原料，采用一步水热法合成蓝色荧光碳量子点。多糖为绿色来源，价格便宜，易得，水溶性低，无药理活性。这些碳量子点表现出良好的荧光稳定性、水溶性、抗干扰性和低细胞毒性，可与Cr(VI)的检测特异性结合形成非荧光复合物引起荧光猝灭，因此可用作一种无标记的纳米传感器。通过内部过滤和静态猝灭效应实现了对 Cr(VI) 的高灵敏度检测。碳点荧光探针的荧光猝灭程度在1-100 μM范围内与Cr(VI)浓度呈良好的线性关系。线性方程为F ₀ / F  = 0.9942 + 0.01472 [Cr(VI)] ( R ² = 0.9922), 检测限可低至 0.25 μM (S/N = 3), 已成功应用于实际水样中 Cr(VI) 的检测。