State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha, Hunan, 410082, PR China.
State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha, Hunan, 410082, PR China.
Anal Chim Acta. 2015 Aug 5;887:45-50. doi: 10.1016/j.aca.2015.07.025. Epub 2015 Aug 10.
In this contribution, surface-enhanced Raman spectroscopy (SERS) based on conical holed glass substrates deposited with silver colloids was reported for the first time. It combines the advantages of both dry SERS assays based on plane films deposited with silver colloids and wet SERS assays utilizing cuvettes or capillary tubes. Compared with plane glass substrates deposited with silver colloids, the conical holed glass substrates deposited with silver colloids exhibited five-to ten-folds of increase in the rate of signal enhancement, due to the internal multiple reflections of both the excitation laser beam and the Raman scattering photons within conical holes. The application of conical holed glass substrates could also yield significantly stronger and more reproducible SERS signals than SERS assays utilizing capillary tubes to sample the mixture of silver colloids and the solution of the analyte of interest. The conical holed glass substrates in combination with the multiplicative effects model for surface-enhanced Raman spectroscopy (MEMSERS) achieved quite sensitive and precise quantification of 6-mercaptopurine in complex plasma samples with an average relative prediction error of about 4% and a limit of detection of about 0.02 μM using a portable i-Raman 785H spectrometer. It is reasonable to expect that SERS technique based on conical holed enhancing substrates in combination with MEMSERS model can be developed and extended to other application areas such as drug detection, environmental monitoring, and clinic analysis, etc.
本文首次报道了基于沉积有银胶体的锥形孔玻璃基底的表面增强拉曼光谱（SERS）。它结合了基于沉积有银胶体的平面膜的干式 SERS 分析以及利用比色皿或毛细管的湿式 SERS 分析的优点。与沉积有银胶体的平面玻璃基底相比，沉积有银胶体的锥形孔玻璃基底的信号增强速率提高了五到十倍，这是由于锥形孔内的激发激光束和拉曼散射光子的内部多次反射。与利用毛细管采样银胶体和感兴趣的分析物溶液的 SERS 分析相比，锥形孔玻璃基底的应用还可以产生更强、更可重现的 SERS 信号。锥形孔玻璃基底与表面增强拉曼光谱的乘法效应模型（MEMSERS）相结合，使用便携式 i-Raman 785H 光谱仪，可实现复杂血浆样品中 6-巯基嘌呤的灵敏、精确定量，平均相对预测误差约为 4%，检测限约为 0.02 μM。可以合理地预期，基于锥形孔增强基底的 SERS 技术与 MEMSERS 模型可以被开发和扩展到其他应用领域，如药物检测、环境监测和临床分析等。
