基于可调控咖啡环效应的表面增强拉曼光谱法检测有机染料  

Surface Enhanced Raman Spectroscopy for Detection of Organic Dyes Based on Adjustable Coffee Ring Effect

作　　者：薛长国[1] 唐毓 李世琴 张宏艳[1] 李本侠 XUE Chang-Guo;TANG Yu;LI Shi-Qin;ZHANG Hong-Yan;LI Ben-Xia(School of Materials Science and Engineering,Anhui University of Science and Technology,Huainan 232001,China;Department of Chemistry,School of Science,Zhejiang Sci-Tech University,Hangzhou 310018,China)

机构地区：[1]安徽理工大学材料科学与工程学院,淮南232001 [2]浙江理工大学理学院化学系,杭州310018

出　　处：《分析化学》2021年第1期151-158,共8页Chinese Journal of Analytical Chemistry

基　　金：国家自然科学基金项目(No.11872001);安徽省自然科学杰出青年科学基金项目(No.1808085J30);安徽省重点研究与开发计划项目(No.202004h07020026)资助。

摘　　要：表面增强拉曼光谱(Surface-enhanced Raman spectroscopy,SERS)是快速、无损检测生物化学物质的良好平台,理论上可检测单个分子水平上的化学物质,但这种潜力受到SERS基底的限制。本研究采用基于可调控咖啡环效应的基底,用于提高SERS在测定痕量分析物时的灵敏度和简便性。通过氧等离子技术改变聚二甲基硅氧烷(Polydimethylsiloxane,PDMS)衬底的表面亲疏水性,进而控制待测染料在衬底上形成的咖啡环形状,考察衬底对拉曼信号的影响;将绿色合成的纳米银颗粒(Silver nanoparticles,AgNPs)与待测染料溶液混合,沉积在PDMS衬底,形成咖啡环,探究拉曼信号的增强效果。结果表明,疏水性的增加,减小了咖啡环的尺寸,提高了咖啡环的紧密度,拉曼信号集中在环上,灵敏度高、重复性好,相对标准偏差(Relative standard deviation,RSD)为5%;咖啡环的形成不仅浓缩了分析物,还减少了AgNPs之间的空间,从而增强了热点效应,SERS检测灵敏度显著提高,检出限达到1×10^-6 mol/L。这种基于咖啡环效应的SERS为废水中染料检测提供了灵敏和环保的方法,具有广阔的应用前景。Surface enhanced Raman spectroscopy(SERS)is an excellent platform for the rapid and non-destructive detection of biochemical substances at monomolecular level.However,this detection technique is limited by the substrate.In this work,a substrate based on the adjustable coffee ring effect was used to improve the sensitivity and simplicity of SERS in determination of trace analytes.The coffee ring shape of the dye was regulated by the surface hydrophilicity of polydimethylsiloxane(PDMS)substrate.Meanwhile,coffee rings with different morphologies would influence the Raman signal,which indirectly explained the influence of substrates on Raman signals.Silver nanoparticles(AgNPs)were mixed with the Congo Red solution and deposited on the PDMS substrate to form a coffee ring,which was used to explore the enhancement effect of Raman signal.The results showed that the coffee rings had smaller size and higher compactness with the increase of hydrophobicity.Besides,the Raman signal was mainly concentrated on the ring and exhibited high sensitivity,excellent repeatability and small relative standard deviation(5%).The coffee ring enhanced the hot spot effect by concentrating the gap between the analyzer and AgNPs,which significantly improved the SERS sensitivity and the detection limit reached 1×10^-6 mol/L.This SERS based on the coffee ring effect provided a sensitive and environmentally friendly method for dyes detection in wastewater,and had a broad application prospect.

关 键 词：表面增强拉曼光谱 聚二甲基硅氧烷 咖啡环 绿色化学 纳米银 有机染料 

分 类 号：X832[环境科学与工程—环境工程] O657.37[理学—分析化学]