Priyadharshini Alagarsamy, Napoleon Ayyakannu Arumugam
Department of Chemistry, School of Advanced Sciences, Vellore Institute of Technology, Vellore 632014, Tamil Nadu, India.
Department of Chemistry, School of Advanced Sciences, Vellore Institute of Technology, Vellore 632014, Tamil Nadu, India.
Spectrochim Acta A Mol Biomol Spectrosc. 2025 May 5;332:125851. doi: 10.1016/j.saa.2025.125851. Epub 2025 Feb 8.
In this study, we successfully synthesized fluorescent carbon dots (CDs) through a one-pot hydrothermal method, utilizing tartaric acid, cysteine, and nickel chloride as precursors. This approach allowed for the incorporation of metal ion (nickel) as well as nitrogen and sulfur heteroatoms into the carbon dot structure, resulting in nickel-doped, nitrogen, and sulfur-co-doped CDs (Ni/NS-CDs). A comprehensive characterization of the Ni/NS-CDs was conducted using FT-IR, XRD, Raman, XPS, and HR-TEM analysis confirmed the successful doping of nickel, nitrogen, and sulfur into the Ni/NS-CDs. HR-TEM analysis showed that the synthesized Ni/NS-CDs were spherical with a well-monodispersed average particle size of 2.1 ± 0.2 nm. The Ni/NS-CDs displayed strong fluorescence with excitation-dependent emission behavior and a high quantum yield of 23.60 %. When excited at 480 nm, the Ni/NS-CDs exhibited bright green emission at 524 nm, showcasing their excellent fluorescent characteristics. Additionally, the Ni/NS-CDs demonstrated remarkable stability across a broad pH range and high salt ionic strengths, further enhancing their practical applicability in diverse environments. The Ni/NS-CDs showed high sensitivity and selectivity towards Mg ions, with an impressively low limit of detection (LOD) of 19.38 nM within a wider range of 0-50 µM. Beyond sensing applications, the bright and stable fluorescence of the Ni/NS-CDs enabled clear cell imaging, making them promising candidates for use in biomedical research and diagnostics. Moreover, the practical utility of the Ni/NS-CDs were successfully applied for detecting Mg ions in environmental samples, illustrating their potential for ecological monitoring and water quality assessment. This broad applicability underscores the multifunctionality of the synthesized Ni/NS-CDs, positioning them as valuable nanomaterials in fields such as pharmaceuticals, bio-imaging, environmental science, and analytical chemistry.
在本研究中，我们通过一锅水热法成功合成了荧光碳点（CDs），使用酒石酸、半胱氨酸和氯化镍作为前驱体。这种方法能够将金属离子（镍）以及氮和硫杂原子引入碳点结构中，从而得到镍掺杂、氮和硫共掺杂的碳点（Ni/NS-CDs）。利用傅里叶变换红外光谱（FT-IR）、X射线衍射（XRD）、拉曼光谱、X射线光电子能谱（XPS）对Ni/NS-CDs进行了全面表征，高分辨透射电子显微镜（HR-TEM）分析证实了镍、氮和硫成功掺杂到Ni/NS-CDs中。HR-TEM分析表明，合成的Ni/NS-CDs呈球形，平均粒径为2.1±0.2nm，分散性良好。Ni/NS-CDs表现出强烈的荧光，具有激发依赖的发射行为，量子产率高达23.60%。当在480nm激发时，Ni/NS-CDs在524nm处发出亮绿色荧光，展示了其优异的荧光特性。此外，Ni/NS-CDs在很宽的pH范围和高盐离子强度下都表现出显著的稳定性，进一步提高了它们在不同环境中的实际适用性。Ni/NS-CDs对镁离子表现出高灵敏度和选择性，在0-50µM的较宽范围内检测限低至19.38nM，令人印象深刻。除了传感应用外，Ni/NS-CDs明亮且稳定的荧光使其能够实现清晰的细胞成像，使其成为生物医学研究和诊断领域有前途的候选材料。此外，Ni/NS-CDs成功应用于环境样品中镁离子的检测，说明了它们在生态监测和水质评估方面的潜力。这种广泛的适用性突出了合成的Ni/NS-CDs的多功能性，使其成为制药、生物成像、环境科学和分析化学等领域有价值的纳米材料。
