Yadav Rajnee, Lahariya Vikas
Department of Physics, Amity School of Applied Sciences, Amity University Haryana, Gurugram, 122413, India.
J Fluoresc. 2025 Aug 18. doi: 10.1007/s10895-025-04487-5.
The detection of toxic metal ions in water is crucial for safeguarding environmental and human health. The study demonstrates a dual-mode fluorescence sensing strategy using boron and nitrogen co-doped carbon quantum dots (BN-CQDs), capable of both significant quenching and emission wavelength shift, for selective detection of Fe (III) and Hg(II) ions. In this study, (BN-CQDs) were synthesized using a green, microwave-assisted approach. Comprehensive characterization revealed that co-doping with boron and nitrogen significantly enhanced the optical and sensing properties of the CQDs. BN-CQDs exhibited a particle size below 5 nm, abundant surface functional groups, and photoluminescence (PL) with a quantum yield of 3.4% against quinine sulphate. It demonstrated remarkable photostability, retaining 92% PL intensity under visible light for 5 h and ionic stability. The prepared BN-CQDs were further used for fluorescence sensing for Fe (III) and Hg(II) ions. The results of zeta potential and TRPL studies is used to elucidate the distinct interaction mechanisms with metal ions. Distinct quenching mechanisms were observed: dynamic quenching for Fe(III) via photoinduced electron transfer (PET) and static quenching for Hg (II) through surface state modification. The detection limits of 0.081 µM for Fe(III) and 0.025 µM for Hg(II), and quantification limits of 0.25 µM (Fe(III)) and 0.075 µM (Hg (II)) present the ability of detection of these metal ions by fluorometric sensor. This study underscores the potential of BN-CQDs as eco-friendly and effective sensors for environmental monitoring.
检测水中的有毒金属离子对于保护环境和人类健康至关重要。该研究展示了一种使用硼氮共掺杂碳量子点（BN-CQDs）的双模式荧光传感策略，该策略能够实现显著的猝灭和发射波长 shift，用于选择性检测铁（III）和汞（II）离子。在本研究中，（BN-CQDs）采用绿色微波辅助方法合成。综合表征表明，硼和氮的共掺杂显著增强了碳量子点的光学和传感性能。BN-CQDs 的粒径小于 5 纳米，具有丰富的表面官能团，相对于硫酸奎宁的量子产率为 3.4%的光致发光（PL）。它表现出显著的光稳定性，在可见光下 5 小时内保持 92%的 PL 强度以及离子稳定性。制备的 BN-CQDs 进一步用于铁（III）和汞（II）离子的荧光传感。zeta 电位和时间分辨光致发光（TRPL）研究结果用于阐明与金属离子的不同相互作用机制。观察到不同的猝灭机制：铁（III）通过光致电子转移（PET）的动态猝灭和汞（II）通过表面状态修饰的静态猝灭。铁（III）的检测限为 0.081 µM，汞（II）的检测限为 0.025 µM，定量限分别为 0.25 µM（铁（III））和 0.075 µM（汞（II）），这表明荧光传感器能够检测这些金属离子。本研究强调了 BN-CQDs 作为用于环境监测的环保且有效传感器的潜力。
