Liang Jiajie, Liu Hongwu, Huang Caihong, Yao Cuize, Fu Qiangqiang, Li Xiuqing, Cao Donglin, Luo Zhi, Tang Yong
§Department of Laboratory Medicine, Guangdong No. 2 Provincial People's Hospital, Guangzhou 510317, People's Republic of China.
Anal Chem. 2015 Jun 2;87(11):5790-6. doi: 10.1021/acs.analchem.5b01011. Epub 2015 May 14.
Lowering the detection limit is critical to the design of bioassays required for medical diagnostics, environmental monitoring, and food safety regulations. The current sensitivity of standard color-based analyte detection limits the further use of enzyme-linked immunosorbent assays (ELISAs) in research and clinical diagnoses. Here, we demonstrate a novel method that uses the Raman signal as the signal-generating system of an ELISA and combines surface-enhanced Raman scattering (SERS) with silver nanoparticles aggregation for ultrasensitive analyte detection. The enzyme label of the ELISA controls the dissolution of Raman reporter-labeled silver nanoparticles through hydrogen peroxide and generates a strong Raman signal when the analyte is present. Using this assay, prostate-specific antigen (PSA) and the adrenal stimulant ractopamine (Rac) were detected in whole serum and urine at the ultralow concentrations of 10(-9) and 10(-6) ng/mL, respectively. The methodology proposed here could potentially be applied to other molecules detection as well as PSA and Rac.
降低检测限对于医学诊断、环境监测和食品安全法规所需的生物测定设计至关重要。基于标准颜色的分析物当前的灵敏度限制了酶联免疫吸附测定（ELISA）在研究和临床诊断中的进一步应用。在此，我们展示了一种新方法，该方法使用拉曼信号作为ELISA的信号生成系统，并将表面增强拉曼散射（SERS）与银纳米颗粒聚集相结合用于超灵敏分析物检测。ELISA的酶标记物通过过氧化氢控制拉曼报告分子标记的银纳米颗粒的溶解，并在存在分析物时产生强烈的拉曼信号。使用该测定法，分别在全血清和尿液中以10^(-9)和10^(-6) ng/mL的超低浓度检测到前列腺特异性抗原（PSA）和肾上腺兴奋剂莱克多巴胺（Rac）。这里提出的方法可能也适用于其他分子的检测以及PSA和Rac的检测。
