College of New Materials and New Energies, Shenzhen Technology University, Shenzhen 518118, PR China; College of Applied Sciences, Shenzhen University, Shenzhen 518060, PR China.
Analysis and Testing Center, Shenzhen Technology University, Shenzhen 518118, PR China.
Ecotoxicol Environ Saf. 2022 Oct 1;244:114069. doi: 10.1016/j.ecoenv.2022.114069. Epub 2022 Sep 14.
Hexavalent chromium (Cr(VI)) determination is of great importance to the public health because of its extensive sources and high toxicity. However, interference from non-target ions and complex matrix remains challenges for Cr(VI) detection. In this work, we constructed a novel sensing system for high selectivity detection of Cr(VI), which is composed of strong emitting carbon dots (CE-CDs) and a specific masking agent. The detection conditions, anti-interference capability and the sensing and masking mechanisms of CE-CDs-based sensing method were systematically investigated. The results revealed that the optimal detection conditions included pH 4-10, reaction time 180 s and CE-CDs concentration 18 mg/L. Under optimal conditions, the linear range of the method was up to 500 µm, and the detection limit was as low as 23 nM. In addition, the interference of Hg(II) can be accurately eliminated by using DMPS, an effective masking agent. During the sensing process, inner filter effect and ion-molecular interaction between Cr(VI) and CE-CDs accounted for the fluorescence quenching mechanism, while the efficient masking was attributed to the strong coordination interaction between Hg(II) and DMPS. Most notably, this method had broad applicability, even for the trace detection of Cr(VI) in colored leather with complex matrix. These findings indicate that this approach is expected to open up new avenues for Cr(VI) detection.
六价铬（Cr(VI)）的测定对于公共健康非常重要，因为它的来源广泛且毒性很高。然而，非目标离子和复杂基质的干扰仍然是 Cr(VI)检测的挑战。在这项工作中，我们构建了一种用于高选择性检测 Cr(VI)的新型传感系统，它由强发射碳点（CE-CDs）和特定的掩蔽剂组成。系统研究了 CE-CDs 基传感方法的检测条件、抗干扰能力以及传感和掩蔽机制。结果表明，最佳检测条件包括 pH 4-10、反应时间 180 s 和 CE-CDs 浓度 18 mg/L。在最佳条件下，该方法的线性范围高达 500 µm，检测限低至 23 nM。此外，使用有效的掩蔽剂 DMPS 可以准确消除 Hg(II)的干扰。在传感过程中，Cr(VI)与 CE-CDs 之间的内滤效应和离子-分子相互作用是荧光猝灭的机制，而高效掩蔽归因于 Hg(II)与 DMPS 之间的强配位相互作用。值得注意的是，该方法具有广泛的适用性，即使对于复杂基质有色皮革中痕量 Cr(VI)的检测也是如此。这些发现表明，这种方法有望为 Cr(VI)检测开辟新途径。
