Institute of Physical Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, 01-224 Warsaw, Poland.
Institute of High Pressure Physics, Polish Academy of Sciences, Sokołowska 29/37, 01-142 Warsaw, Poland.
Biosens Bioelectron. 2015 Apr 15;66:461-7. doi: 10.1016/j.bios.2014.10.082. Epub 2014 Nov 13.
A highly sensitive immunoassay utilizing surface-enhanced Raman scattering (SERS) has been developed with a new Raman reporter and a unique SERS-active substrate incorporated into a microfluidic device. An appropriately designed Raman reporter, basic fuchsin (FC), gives strong SERS enhancement and has the ability to bind both the antibody and gold nanostructures. The fuchsin-labeled immuno-Au nanoflowers can form a sandwich structure with the antigen and the antibody immobilized on the SERS-active substrate based on Au-Ag coated GaN. Our experimental results indicate that this SERS-active substrate with its strong surface-enhancement factor, high stability and reproducibility plays a crucial role in improving the efficiency of SERS immunoassay. This SERS assay was applied to the detection of Hepatitis B virus antigen (HBsAg) in human blood plasma. A calibration curve was obtained by plotting the intensity of SERS signal of FC band at 1178cm(-1) versus the concentration of antigen. The low detection limit for Hepatitis B virus antigen was estimated to be 0.01IU/mL. The average relative standard deviation (RSD) of this method is less than 10%. This SERS immunoassay gives exact results over a broad linear range, reflecting clinically relevant HBsAg concentrations. It also exhibits high biological specificity for the detection of Hepatitis B virus antigen.
一种利用表面增强拉曼散射（SERS）的高灵敏度免疫分析已经被开发出来，该方法将新型拉曼报告分子和独特的 SERS 活性基底整合到微流控器件中。一个设计合理的拉曼报告分子，碱性品红（FC），具有很强的 SERS 增强能力，并且能够同时结合抗体和金纳米结构。标记有品红的免疫-Au 纳米花可以与抗原形成三明治结构，而抗体则固定在基于 Au-Ag 涂层 GaN 的 SERS 活性基底上。我们的实验结果表明，这种具有强表面增强因子、高稳定性和重现性的 SERS 活性基底在提高 SERS 免疫分析效率方面起着至关重要的作用。该 SERS 分析应用于检测人血浆中的乙型肝炎病毒抗原（HBsAg）。通过绘制 1178cm(-1)处 FC 带的 SERS 信号强度与抗原浓度的关系得到校准曲线。乙型肝炎病毒抗原的检测下限估计为 0.01IU/mL。该方法的平均相对标准偏差（RSD）小于 10%。该 SERS 免疫分析在较宽的线性范围内给出了准确的结果，反映了临床相关的 HBsAg 浓度。它还表现出对乙型肝炎病毒抗原检测的高生物学特异性。
