电热诱导抓捕分析物的高灵敏度复合纳米结构表面增强拉曼散射系统

项目名称： 电热诱导抓捕分析物的高灵敏度复合纳米结构表面增强拉曼散射系统

项目编号： No.51472245

项目类型： 面上项目

立项/批准年度： 2015

项目学科： 一般工业技术

项目作者： 孟国文

作者单位： 中国科学院合肥物质科学研究院

项目金额： 89万元

中文摘要： 表面增强拉曼散射(SERS)可望用于痕量物质的快速鉴别。该技术要求衬底既具有高的活性、又能抓捕待检物。SERS来源于贵金属的电磁增强和半导体的化学增强作用。本项目首先在电热丝上生长ZnO纳米锥阵列；再在纳米锥上生长高密度Ag纳米颗粒；然后将其置入毛细管内，在电热丝与毛细管间，充填温敏水凝胶、Au纳米棒和待检物的混合体，形成既能抓捕待检物、又具有高SERS活性的复合系统。其中，ZnO具有化学增强作用；Ag颗粒之间、Au棒之间以及Ag颗粒与Au棒之间，均具有电磁增强作用。尤为重要的是，当电热丝加热时，温敏水凝胶收缩，不仅使Au棒之间相互靠拢，提高SERS活性；而且也使Au棒与Ag颗粒靠近，提高SERS活性。同时，伴随水凝胶分子链的收缩，将待检物拉近Au颗粒和Ag棒，起到了抓捕待检物的作用。因此，系统不仅具有很高的SERS敏感性，而且能有效抓捕待检物。对高毒性污染物的快速痕量检测具有重要的意义。

中文关键词： 纳米结构；纳米功能材料；光电功能材料；可控制备；光电性能

英文摘要： Surface-enhanced Raman scattering (SERS) effect based technique has promising potential in rapid identification of analytes with high sensitivity and fingerprint characteristics. The key issues for SERS-based analysis is to build substrates with not only high SERS-activity but also good ability to capture the target analytes, however it is difficult to simultaneously achieve these two goals using the current synthetic approaches. From the view point of high SERS activity, it has been reported that nanostructures of noble metals have electromagnetic coupling induced SERS enhancement, and semiconductor nanoscale-frameworks have chemical supporting SERS enhancement. From the view point of capturing the target analyte molecules, chemical modification and mechanical trapping have been used. In order to achieve SERS system with both high SERS-activity and ability to capture target analyte molecules, in this project we will design and build a small battery (electric heating) controlled composite SERS system with much higher SERS-activity and ability to capture the analyte molecules for rapid trace analysis of highly toxic pollutants in aqueous solution. Firstly, arrays of radial semiconductor ZnO nanotapers are electrodeposited on an electric heating constantan wire, then high density of Ag-nanoparticles are decorated onto each ZnO-nanotaper, next the above-built electric heating constantan with ZnO-nanotapers and Ag-nanoparticles is inserted into a glass capillary, and finally the analyte solution and Au-nanorods colloids as well as thermo-responsive pNIPAM microgels are mixed and injected into the remnant empty room of the capillary. The compact composite microfluidic SERS system will have much higher SERS-activity as the electromagnetic enhancement of neighboring Au-nanorods, the Au-nanorods and their nearby Ag-nanoparticles decorated on ZnO-nanotapers, and the chemical supporting enhancement of ZnO-nanotapers all have contributions to the SERS activity. Furthermore if the circuit is switched on and the system is heated up to about 32oC, the thermo-responsive pNIPAM microgels will shrink, leading to not only trapping (capturing) the analyte molecules closer to the plasmonic Au-nanorods and Ag-nanoparticles decorated on ZnO-nanotapers but also abridging the spacing of the neighboring Au-nanorods, and that of the Au-nanorods and their nearby Ag-nanoparticles decorated on ZnO-nanotapers, thus the SERS-sensitivity is much improved. As such, multiple noble metal electromagnetic enhancement, semiconductor chemical supporting enhancement and effective trapping of the analyte are realized in a simple battery-powered (electric heating) controlled compact microfluidic system, and the composite SERS system has promising potentials in SERS-based rapid trace analysis of highly toxic pollutants in aqueous solution samples.

英文关键词： Nanostructures;Nano-scale functional materials;optoelectronic functional materials;Controlled synthesis;Optical property