在小分子有机酸电解液中，以高纯石墨棒为工作电极，通过一步电解刻蚀法剥落制备荧光性碳纳米颗粒（carbon dots，CDs）。通过分析不同电解底液制得碳点溶液的光谱性质，探究碳点可能的发光机理。实验结果表明，相同条件下电解得到的碳点的发光性能受有机酸底液类型影响明显，不同底液制得的碳点可能具有不同表面结构基团，从而推测此方法制备碳点的发光机理为表面态发光。半胱氨酸碳点（cysteine carbon dots，CECDs）具有较高的荧光量子产率和较好的光稳定性，并且呈现出不同于有机荧光染料分子的光谱依赖性。基于银离子对碳点荧光信号的猝灭作用，可将其作为荧光探针检测银离子的含量。荧光猝灭率（F₀/F）与银离子浓度在1.00×10^-8~2.30×10^-7mol/L范围内呈现良好的线性关系，相关系数为0.990 9。

Fluorescent carbon dots (CDs) are obtained through one-step electrolytic etching method with high-purity graphite rods as working electrodes in organic acids electrolytes.The optically stimulated luminescence emission mechanism of CDs is explored by researching the optical properties of carbon dots solutions prepared in different electrolytic solutions.Under the same electrolysis conditions,the luminescent properties of the carbon dots are significantly affected by the type of organic acid electrolyte.Experimental results indicate that CDs prepared by different base solutions may have different surface structure groups.Therefore,it can be inferred that surface luminescence is the luminescence mechanism of carbon dots by this method.Cysteine carbon dots (CECDs) prepared in the cysteine solution owns higher fluorescence quantum yield and better light stability,and shows spectral dependence that differs from organic fluorescent dye molecules.Silver ions (Ag⁺) can quench the fluorescence signals of CECDs,which can be used as a fluorescent probe to detect the content of Ag⁺.The fluorescence quenching rate (F₀/F) of CECDs shows a good linear relationship with the concentration of silver ion in the range of 1.00×10^-8-2.30×10^-7 mol·L^-1 with a correlation coefficient of 0.990 9.

杨建梅(1996-),女,本科生