Mahmud Chnar Z, Fakhre Nabil A
Department of Chemistry, College of Education, Salahaddin University-Erbil, Erbil, Iraq.
Tishk International University, Erbil, Iraq.
J Fluoresc. 2025 Jun 17. doi: 10.1007/s10895-025-04386-9.
In this research, the carbon quantum dots (CQDs) with a particle size of 8.0 nm, quantum yield (17.8) and long period of stability 60 days were prepared under a simple, eco-friendly, low-toxic and low-cost one-step hydrothermal method by employing biomass rheum ribes (R. ribes) as precursors for detection purpose. The widely recognized heavy metal element is lead (Pb⁺), and the pollution it causes has received considerable attention. Therefore, it is both essential and extremely difficult to develop uncomplicated and efficient techniques for the detection of lead ions (Pb⁺) in kids' toy samples. The study focused on the detection of lead ions (Pb) in kids' toy samples. The presence of heavy metals in toys poses significant health risks such as cancer, kidney disorder, behavioural disorders, increased aggression bone and brain tissues, due to their potential toxicity and bioaccumulation. Lead is a global priority pollutant. The investigated results were processed by a fluorescence spectrophotometer under optimum conditions with excitation and emission wavelengths of 330nm and 406nm, respectively. Fluorescence of CQDs was quenched efficiently and sensitively by lead (Pb) ions, throughout some other common metal ions. The linear range is wide (0.01-21.0μg/mL) with the detection limit (0.00974μg/mL), limit of quantification (0.0325μg/mL), and (R = 0.9939). The recovery of Pb⁺ ions, which cause quenching of fluorescence intensity, was mostly more than 90% (n = 3). The results show high contents of Pb in kids' toy samples. The concentration of Pb⁺ in the samples under study was over 100μg/mL after multiplying the corresponding dilution factors. The intense quenching effect of carbon dots can be attributed to the efficient binding of lead ions on their surface. Later, it was proposed and established that aggregation-induced quenching is the working principle of carbon dots' interaction with Pb⁺ ions.
在本研究中，采用生物质大黄（R. ribes）作为前驱体，通过简单、环保、低毒且低成本的一步水热法制备了粒径为8.0 nm、量子产率为17.8且具有60天长期稳定性的碳量子点（CQDs），用于检测目的。广泛认可的重金属元素是铅（Pb⁺），其造成的污染已受到相当多的关注。因此，开发用于检测儿童玩具样品中铅离子（Pb⁺）的简单高效技术既至关重要又极具挑战性。该研究聚焦于检测儿童玩具样品中的铅离子（Pb）。玩具中重金属的存在会带来重大健康风险，如癌症、肾脏疾病、行为障碍、骨骼和脑组织的攻击性增强，这是由于它们具有潜在毒性和生物累积性。铅是全球重点污染物。在最佳条件下，使用荧光分光光度计对研究结果进行处理，激发波长和发射波长分别为330nm和406nm。与其他一些常见金属离子相比，铅（Pb）离子能有效且灵敏地猝灭CQDs的荧光。线性范围宽（0.01 - 21.0μg/mL），检测限为（0.00974μg/mL），定量限为（0.0325μg/mL），相关系数（R = 0.9939）。导致荧光强度猝灭的Pb⁺离子回收率大多超过90%（n = 3）。结果表明儿童玩具样品中铅含量很高。在乘以相应稀释因子后，所研究样品中Pb⁺的浓度超过100μg/mL。碳点的强烈猝灭效应可归因于铅离子在其表面的有效结合。后来，有人提出并证实聚集诱导猝灭是碳点与Pb⁺离子相互作用的工作原理。
