Shi Xiaofeng, Liu Shu, Han Xiaohong, Ma Jun, Jiang Yongchao, Yu Guifeng
Optics and Optoelectronics Laboratory, Ocean University of China, Qingdao 266100, China.
Appl Spectrosc. 2015 May;69(5):574-9. doi: 10.1366/14-07614R.
In this study, a gold colloid solution whose parameters were optimized, and without any surfactants, was developed as a surface-enhanced Raman scattering (SERS) substrate for the detection of trace-level polycyclic aromatic hydrocarbons (PAHs). A gold colloid solution with 57 nm gold particles and pH 13 was prepared to be the SERS substrate. It had impressive enhancement that was two orders of magnitude higher than that of a gold colloid solution with 57 nm gold particles and without pH change (pH 6). Even with a compact field-based Raman spectrometer, naphthalene, phenanthrene, anthracene, fluoranthene, and pyrene were detected, with limits of detection at 6.8 nM, 3.4 nM, 1.8 nM, 0.68 nM (680 pM), and 0.44 nM (440 pM), respectively. The significant enhancement was ascribed to an electromagnetic mechanism and a charge-transfer mechanism. Quantitative analyses for these five PAHs in water were also performed. The SERS intensities of PAHs were found to have good linear dependence relations with the concentrations in low concentration. This high-sensitivity, easily prepared substrate offers a promising technology for the quantitative detection of trace-level PAHs.
在本研究中，开发了一种参数经过优化且不含任何表面活性剂的金胶体溶液，作为用于检测痕量多环芳烃（PAHs）的表面增强拉曼散射（SERS）基底。制备了具有57 nm金颗粒且pH值为13的金胶体溶液作为SERS基底。其增强效果令人印象深刻，比具有57 nm金颗粒且pH值不变（pH 6）的金胶体溶液高出两个数量级。即使使用紧凑型现场拉曼光谱仪，也检测到了萘、菲、蒽、荧蒽和芘，检测限分别为6.8 nM、3.4 nM、1.8 nM、0.68 nM（680 pM）和0.44 nM（440 pM）。显著的增强归因于电磁机制和电荷转移机制。还对水中的这五种多环芳烃进行了定量分析。发现多环芳烃的SERS强度在低浓度下与浓度具有良好的线性依赖关系。这种高灵敏度、易于制备的基底为痕量多环芳烃的定量检测提供了一种有前景的技术。
