N-掺杂的荧光碳点比率识别Ag^(+)的性能

N-Doped Carbon Dots with Ratio Fluorescent Detection for Ag^(+)

以中性红和甲酰胺为前驱体,通过一步水热法合成了粒径约为3.88 nm的氮掺杂的碳点(N-CDs)。该碳点具有好的水溶性和光稳定性,并且与Ag^(+)的结合呈比率荧光发射的特点,基于此建立了测定Ag^(+)的一种新分析方法,进一步考察了离子强度、pH的变化对N-CDs荧光强度的影响。在优化条件下,Ag^(+)浓度在0~12μmol/L的范围与荧光强度的比值(520/580 nm)呈现良好的线性关系,检测限为0.14μmol/L。干扰研究显示碳点对Ag^(+)具有高的灵敏度和好的选择性。二者相互作用的研究表明,碳点通过表面的胺基与Ag^(+)结合而实现其选择性识别。将碳点N-CDs应用于实际水样(自来水、泉水和河水)中Ag^(+)的检测,加标回收率在98.5%~104.2%之间。

Nitrogen doped carbon dots(N-CDs)with an average size of 3.88 nm were prepared via a one-pot hydrothermal method by using neutral red and formamide as the carbon precursors.The as-synthesized N-CDs exhibit excellent water dispersibility as well as good photostability.Moreover,on the basis of ratiometric fluorescence emission characteristics by the interaction between N-CDs and Ag^(+),a new analytic method has been developed,and the effects of ionic strength and pH on N-CDs are estimated.Under the optimized condition,a good linearity is presented between the Ag^(+)concentration in the range of 0~12μmol/L and the fluorescence intensity ratio at 520 and 580 nm(520/580 nm).The detection limit is 0.14μmol/L.The interference research shows that N-CDs have high sensitivity and selectivity for Ag^(+),which could be attributed to the amino groups on the surface of the N-CDs that could bind to Ag^(+)and form the complex of N-CDs-Ag^(+).In addition,the test results based on different water samples(tap water,spring water and river water)for Ag^(+)detection show that the recoveries are within 98.5%~104.2%.