高灵敏度快速表面增强拉曼光谱与微型气相色谱技术联用提高复杂样品分析能力的可行性研究

The objective of the proposed research is to study the feasibility of using two combined technologies of surface enhanced Raman spectroscopy (SERS) and micro-gas chromatography (MGC) to increase gas mixtures analysis capability. MGC is a particularly attractive technology for networked environmental monitoring due to its small size, low power consumption, and capability for analyzing gas mixtures of arbitrary composition. However, due to the limited length of the separation columns employed, it suffers from inherently low chromatographic resolution which makes it impossible to identify the analytes embedded in co-eluted peaks and limits the complexity of the mixtures that MGC can effectively analyze. The proposed research will combine an enhanced SERS sensing technology with MGC to address the above inherent limitation, by providing two independent identification algorisms. The SERS sensing technique can produce the molecular signature of each gas analyte, which can be potentially used to identify the gas analytes coeluted from MGC column. However, traditional SERS has very slow response and sensitivity, which hardly satisfies the stringent detection requirements of MGC. Our approach to solve this problem is to optimize the manufacturing and assembling methods of gold nanoparticles to obtain the fastest response and highest sensitivity. Finally, the SERS and MGC technologies will be combined to analyze ubiquitous environmental contaminants in complex mixtures and the result will be used to demonstrate the feasibility of using these two technologies to improve the identification resolution of gas mixtures.

本项目研究表面增强拉曼光谱（SERS）与微型气相色谱（MGC）技术的联用对提高气体样品分辨率的可行性。MGC技术的装置体积小、能耗低、能分离含有任意成分的样品，适用于实地快速的环境监测。但由于MGC技术采用比传统色谱技术短很多的色谱柱分离样品，导致多个样品成分同时排出色谱柱无法用色谱技术辨认，限制了可被该技术有效分离的样品的复杂度。为了解决这个问题本项目提出将SERS技术与MGC技术联用的方法提高气体样品的分辨率。SERS技术能识别分子结构信息，因此可以通过辨别分子结构将多个同时排出色谱柱的成分区分开。然而传统的SERS技术不仅反应速度慢而且灵敏度低，不满足MGC技术快速探测的要求。本项目将通过研究金纳米颗粒不同制作和组装方法提高SERS的探测速度和灵敏度与MGC技术的探测要求匹配。最后本项目将结合SERS与MGC技术共同分析常见环境污染物并评估两种技术的联用对提高分辨样品成分的可行性。

在本基金的资助下，我们按照计划对金纳米颗粒SERS气体传感器及其与微型气相色谱的集成开展了研究。三年来，研究进展顺利，完成研究目标。三年来，主要研究成果以论文、专利和学术会议报告的形式体现。共发表SCI收录的论文4篇，其中一区论文2篇，申请发明专利4项，做国际和国内特邀报告各1次。主要研究成果有：.1）将光学测试系统集成在硅基微流道内，测试了其对气体的高灵敏度快速响应，进而实现与微型气相色谱仪的集成。.2）用沉积金膜和退火这两步常规工艺，在二维纳层状材料上制备金纳米颗粒。发现金膜在不同的二维层状材料上退火后，浸湿形貌差异巨大。.3）以石墨烯和碲化钼这两种二维层状材料为代表，用上述工艺方法制备的二维材料/金纳米颗粒结构为拉曼基底，测试了其气体探测能力，探测灵敏度比以硅/二氧化硅/金纳米颗粒结构的基底高。.4）探索了液相大规模制备基于二维材料/金纳米颗粒的拉曼基底的可行性。