Bhatt Madhuri, Bhatt Shreya, Vyas Gaurav, Raval Ishan, Kumar Anshu, Paul Parimal
Analytical and Environmental Science Division & Centralized Instrument Facility, CSIR-Central Salt and Marine Chemicals Research Institute, G. B. Marg, Bhavnagar, 364002, India.
Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, 201002, India.
J Fluoresc. 2025 Mar;35(3):1457-1466. doi: 10.1007/s10895-024-03602-2. Epub 2024 Feb 17.
Fluorescent carbon dots (Trp-CDs) were prepared using tryptophan as precursor and were characterized on the basis of elemental analysis, powder-XRD, IR, Raman spectroscopy, C-NMR, UV-Vis, fluorescence and TEM. Trp-CDs exhibit poor fluorescence in 100% water but showed strong Aggregation Induced Emission (AIE) in ethanol and higher alcohols. The anion sensing study of Trp-CD revealed that it selectively detects CN and CrO and from fluorescence quenching titration study, quenching constant, LOD and range of detection were evaluated. The emission life-time of Trp-CD before and after addition of CN and CrO were measured, the decay curve before addition of anion was best fitted with a bi-exponential function with life-time of τ1 2.79 ns (10.74%) and τ2 18.93 ns (89.26%). The mechanistic study revealed that for CN, the fluorescence quenching is due to its interaction with protons attached to surface functional groups and for CrO, it is due to inner filter effect (IFE). Sensing strips were prepared by coating Trp-CDs onto various solid surfaces including agarose films and were used for detection of CN and CrO. Trp-CD was found to be nontoxic and biocompatible and used as staining agent for Artemia and Bacteria (Bacillus Subtilis, Pseudomonas) and detection of CN and CrO.
以色氨酸为前驱体制备了荧光碳点（Trp-CDs），并通过元素分析、粉末X射线衍射、红外光谱、拉曼光谱、碳核磁共振、紫外可见光谱、荧光光谱和透射电子显微镜对其进行了表征。Trp-CDs在100%水中荧光较弱，但在乙醇和高级醇中表现出强烈的聚集诱导发光（AIE）。对Trp-CD的阴离子传感研究表明，它能选择性地检测CN⁻和CrO₄²⁻，通过荧光猝灭滴定研究，评估了猝灭常数、检测限和检测范围。测量了添加CN⁻和CrO₄²⁻前后Trp-CD的发射寿命，添加阴离子前的衰减曲线最佳拟合为双指数函数，寿命τ₁为2.79 ns（10.74%），τ₂为18.93 ns（89.26%）。机理研究表明，对于CN⁻，荧光猝灭是由于其与附着在表面官能团上的质子相互作用，对于CrO₄²⁻，是由于内滤效应（IFE）。通过将Trp-CDs涂覆在包括琼脂糖膜在内的各种固体表面上制备传感条，并用于检测CN⁻和CrO₄²⁻。发现Trp-CD无毒且具有生物相容性，并用作卤虫和细菌（枯草芽孢杆菌、假单胞菌）的染色剂以及CN⁻和CrO₄²⁻的检测。
