Bavya Vallil, Rajan Thazhavilai Ponnu Devaraj, Suresh Kattimuttathu Ittara
Materials Science and Technology Division, CSIR─National Institute for Interdisciplinary Science and Technology, Pappanamcode, Thiruvananthapuram 695019, Kerala, India.
Research Centre, University of Kerala, Thiruvananthapuram 695034, Kerala, India.
Langmuir. 2025 Jan 21;41(2):1333-1343. doi: 10.1021/acs.langmuir.4c03942. Epub 2025 Jan 10.
Mercury contamination of the environment is extremely hazardous to human health because of its significant toxicity, especially in water. Biomass-derived fluorophores such as carbon dots (CDs) have emerged as eco-friendly and cost-effective alternative sensors that provide comparable efficacy while mitigating the environmental and economic drawbacks of conventional methods. In this work, we report the fabrication of a selective fluorescence-enhancing sensor based on sulfur-doped carbon dots (SCDs) using waste bamboo-derived cellulose and sodium thiosulfate as the soft base dopant, which actively complexes with mercury ions for detection. SCDs with an average size of 4 nm were synthesized hydrothermally, and the sulfur doping was confirmed quantitatively with an atomic percentage of 6.5%. Optical studies reveal an abnormal fluorescence enhancement of SCD in the presence of mercury due to the aggregation of carbon dots via sulfur-containing functional groups. The fabricated sensor exhibits a low detection limit of 5.16 nM, suggesting its application potential as a reliable mercury sensor. Real-time analyses carried out using tap water samples spiked with mercury and industry samples showed high efficiency for Hg(II) detection. The sensing performance was also demonstrated by using SCD-coated filter paper strips.
由于汞对环境的污染具有极高的毒性，尤其是在水中，因此对人类健康危害极大。生物质衍生的荧光团，如碳点（CDs），已成为一种环保且经济高效的替代传感器，其功效相当，同时减轻了传统方法的环境和经济弊端。在这项工作中，我们报告了一种基于硫掺杂碳点（SCDs）的选择性荧光增强传感器的制备方法，该方法使用废弃竹材衍生的纤维素和硫代硫酸钠作为软碱掺杂剂，后者与汞离子发生主动络合以进行检测。通过水热法合成了平均尺寸为4 nm的SCDs，并通过6.5%的原子百分比定量确认了硫掺杂。光学研究表明，由于含硫官能团导致碳点聚集，在汞存在的情况下SCD会出现异常的荧光增强。所制备的传感器具有5.16 nM的低检测限，表明其作为可靠汞传感器的应用潜力。使用添加了汞的自来水样品和工业样品进行的实时分析显示，该传感器对Hg(II)的检测效率很高。使用涂有SCD的滤纸也证明了其传感性能。
