Faculty of Physics, Babeş-Bolyai University, Cluj-Napoca, Romania.
Anal Bioanal Chem. 2011 May;400(3):815-20. doi: 10.1007/s00216-011-4798-5. Epub 2011 Feb 26.
A new, simple, and effective approach for multianalyte sequential surface-enhanced Raman scattering (SERS) detection in a flow cell is reported. The silver substrate was prepared in situ by laser-induced photochemical synthesis. By focusing the laser on the 320 μm inner diameter glass capillary at 0.5 ml/min continuous flow of 1 mM silver nitrate and 10 mM sodium citrate mixture, a SERS active silver spot on the inner wall of the glass capillary was prepared in a few seconds. The test analytes, dacarbazine, 4-(2-pyridylazo)resorcinol (PAR) complex with Cu(II), and amoxicillin, were sequentially injected into the flow cell. Each analyte was adsorbed to the silver surface, enabling the recording of high intensity SERS spectra even at 2 s integration times, followed by desorption from the silver surface and being washed away from the capillary. Before and after each analyte passed the detection window, citrate background spectra were recorded, and thus, no "memory effects" perturbed the SERS detection. A good reproducibility of the SERS spectra obtained under flow conditions was observed. The laser-induced photochemically synthesized silver substrate enables high Raman enhancement, is characterized by fast preparation with a high success rate, and represents a valuable alternative for silver colloids as SERS substrate in flow approaches.
报道了一种新的、简单有效的多分析物顺序表面增强拉曼散射（SERS）检测方法，该方法在流动池中使用。通过将激光聚焦在 320μm 内径的玻璃毛细管上，以 0.5ml/min 的连续流速流过 1mM 硝酸银和 10mM 柠檬酸钠混合物，几秒钟内就在玻璃毛细管的内壁上制备了具有 SERS 活性的银点。测试分析物，达卡巴嗪、与 Cu(II) 的 4-(2-吡啶偶氮)间苯二酚（PAR）络合物和阿莫西林，顺序注入流动池。每个分析物都被吸附到银表面上，即使在 2s 的积分时间内，也能记录到高强度的 SERS 光谱，然后从银表面解吸并从毛细管中冲洗掉。在每个分析物通过检测窗口之前和之后，都会记录柠檬酸背景光谱，因此，没有“记忆效应”干扰 SERS 检测。在流动条件下获得的 SERS 光谱具有良好的重现性。激光诱导光化学合成的银基底具有较高的拉曼增强作用，其制备速度快、成功率高，是流动方法中 SERS 基底的胶体银的一种有价值的替代品。
