Department of Electronics and Electrical Engineering, University of Glasgow, Rankine Building, Oakfield Avenue, Glasgow G12 8LT, UK.
Anal Chem. 2010 Mar 1;82(5):2119-23. doi: 10.1021/ac100060g.
We demonstrate the enhanced analytical sensitivity of both surface enhanced Raman scattering (SERS) and surface enhanced resonance Raman scattering (SERRS) responses, resulting from the in situ synthesis of silver colloid in a microfluidic flow structure, where both mixing and optical interrogation were integrated on-chip. The chip-based sensor was characterized with a model Raman active label, rhodamine-6G (R6G), and had a limit of detection (LOD) of ca. 50 fM (equivalent to single molecule detection). The device was also used for the determination of the natural pigment, scytonemin, from cyanobacteria (as an analogue for extraterrestrial life existing in extreme environments). The observed LOD of approximately 10 pM (ca. <400 molecules) demonstrated the analytical advantages of working with freshly synthesized colloid in such a flow system. In both cases, sensitivities were between 1 and 2 orders of magnitude greater in the microfluidic system than those measured using the same experimental parameters, with colloid synthesized off-chip, under quiescent conditions.
我们展示了表面增强拉曼散射（SERS）和表面增强共振拉曼散射（SERRS）响应的分析灵敏度增强，这是由于在微流控流动结构中就地合成银胶体，从而实现了混合和光学检测的芯片内集成。基于芯片的传感器采用模型拉曼活性标记物罗丹明-6G（R6G）进行了表征，其检测限（LOD）约为 50 fM（相当于单分子检测）。该器件还用于测定蓝细菌中的天然色素藻蓝蛋白（作为存在于极端环境中的外星生命的模拟物）。观察到的约 10 pM 的 LOD（约 <400 个分子）表明，在这种流动系统中使用新鲜合成胶体具有分析优势。在这两种情况下，与在静态条件下在离芯片合成胶体并使用相同实验参数测量相比，微流控系统中的灵敏度均提高了 1 到 2 个数量级。
