蒲地蓝药渣氮掺杂碳点制备及对Fe^(3+)检测分析

Preparation of Nitrogen-doped Carbon Dots and Analysis of Fe^(3+)Detection in Pudilan Residue

基于生物质碳点(carbon dots,CDs)作为新型的荧光碳纳米材料,因其具备较好的生物相容性、低细胞毒性等优点,在荧光成像、环境检测等领域受到广泛关注。利用煎煮后的蒲地蓝原材料制备CDs,其市场需求量大导致大量残渣被浪费,且当前将多种中药组合制备成CDs的文章鲜有报道。针对上述问题,以蒲地蓝残渣作为碳源,三乙胺为氮源,采用水热法制备氮掺杂CDs(Nitrogen doped carbon dots,N-CDs)。首先,结合单因素试验与正交试验,最终确定N-CDs的最佳工艺条件为蒲地蓝药渣1.2 g、反应温度220℃、三乙胺0.4 mL、反应时间8 h;其次,将该条件下的N-CDs进行紫外和荧光光谱的检测,N-CDs紫外吸收峰位于268 nm处,最佳激发和发射峰分别位于320 nm和412 nm,量子产率为6.48%;最后,利用红外、XRD、TEM对N-CDs进行形貌分析,结果表明N-CDs属于无定形碳,且表面富含羟基、羰基等官能团,平均粒径为7.08 nm。此外,将N-CDs用于Fe3+检测,N-CDs的荧光猝灭程度与0.2~20μmol/L的Fe^(3+)浓度呈良好的线性关系,线性方程为y=0.00598c+0.00792(R2=0.9969),检出限为0.31μmol/L。该检测方法操作简单,成本低,选择性好。

Biomass carbon dots(CDs),as a new type of fluorescent carbon nanomaterials,has been widely concerned in the fields of fluorescence imaging and environmental detection due to its advantag-es of good biocompatibility and low cytotoxicity.CDs prepared from Pudilan after decocting has been wasted due to its large market demand,and there are few reports on the preparation of CDs by combin-ing various traditional Chinese medicines.To solve these problems,nitrogen doped carbon dots(N-CDs)were prepared by hydrothermal method using Pudilan residue as carbon source and triethyl-amine as nitrogen source.Firstly,combined with single factor test and orthogonal test,the optimal pro-cess conditions of N-CDs were determined as follows:Pudilan residue 1.2 g,reaction temperature 220℃,triethylamine 0.4 mL,reaction time 8 h.Secondly,the ultraviolet and fluorescence spectra of N-CDs under this condition were detected.The ultraviolet absorption peak of N-CDs was 268 nm,the optimal excitation and emission peaks were 320 nm and 412 nm,respectively,and the quantum yield was 6.48%.Finally,the morphology of N-CDs was analyzed by infrared,XRD and TME.The results show that N-CDs belong to amorphous carbon,and its surface is rich in hydroxyl,carbonyl and other functional groups,with an average particle size of 7.08 nm.In addition,the fluorescence quenching de-gree of N-CDs was linearly correlated with the concentration of Fe^(3+)from 0.2 to 20μmol/L.The lin-ear equation was y=0.00598c+0.00792(R^(2)=0.9969),and the detection limit was 0.31μmol/L.This detection method has the advantages of simple operation,low cost and good selectivity.