Zheng Ziyuan, Zhou Zhengwei
School of Environmental Science and Engineering, Changzhou University, Changzhou 213164, China.
Sensors (Basel). 2025 Sep 5;25(17):5554. doi: 10.3390/s25175554.
In this study, blue fluorescence carbon dots of high quantum yield (42.96%) were successfully synthesized via a one-step hydrothermal method using residues as the precursor and urea as the nitrogen source. The preparation process was simple, was environmentally friendly, and did not use toxic chemicals, with the resulting nitrogen-doped carbon dots (N-PCDs) exhibiting excellent dispersibility, regular morphology and stable fluorescence performance. Moreover, fluorescence quenching could be induced through electron transfer between N-PCDs and hexavalent chromium (Cr(VI)) in water, which enabled the application of N-PCDs as a fluorescent probe for sensing Cr(VI) in water, with a limit of detection (LOD) and limit of quantitation (LOQ) of 0.078 μM and 0.26 μM, respectively. The effectiveness of the proposed fluorescent probe was also validated in various water matrices, achieving stable recovery rates ranging from 98.7% to 101.5%. Furthermore, experimental investigations and theoretical calculations through density functional theory (DFT) confirmed that the underlying reaction mechanism was photoinduced electron transfer (PET). Above all, this study not only demonstrated the potential of N-PCDs as sensitive probes to sense toxic elements in the environment, but also promotes the green and scalable production of high-value carbon-based products from waste biomass.
在本研究中，以残渣为前驱体、尿素为氮源，通过一步水热法成功合成了具有高量子产率（42.96%）的蓝色荧光碳点。制备过程简单、环保，且不使用有毒化学品，所得的氮掺杂碳点（N-PCDs）具有优异的分散性、规则的形态和稳定的荧光性能。此外，通过水中N-PCDs与六价铬（Cr(VI)）之间的电子转移可诱导荧光猝灭，这使得N-PCDs能够作为一种荧光探针用于检测水中的Cr(VI)，其检测限（LOD）和定量限（LOQ）分别为0.078 μM和0.26 μM。所提出的荧光探针在各种水基质中也得到了验证，回收率稳定在98.7%至101.5%之间。此外，通过密度泛函理论（DFT）进行的实验研究和理论计算证实，其潜在的反应机理是光诱导电子转移（PET）。最重要的是，本研究不仅证明了N-PCDs作为灵敏探针检测环境中有毒元素的潜力，还促进了从废弃生物质中绿色、规模化生产高价值碳基产品。
