SERS-based immunoassay using gold-patterned array chips for rapid and sensitive detection of dual cardiac biomarkers

Cardiac troponin I (cTnI) and creatine kinase-MB (CK-MB) are important diagnostic biomarkers for acute myocardial infarction (AMI). Many efforts have been undertaken to develop highly sensitive detection methods for the quantitative analysis of these dual targets. However, current immunoassay methods are inadequate for accurate measurement of cTnI and CK-MB, due to their limited detection sensitivity. Thus, there is still an urgent demand for a new technique that will enable ultrahigh sensitive detection of these biomarkers. In this study, we developed a surface-enhanced Raman scattering (SERS)-based sandwich immunoassay platform for the ultrasensitive detection of cTnI and CK-MB. In this study, a monoclonal-antibody-immobilized gold-patterned chip was used as a SERS active template. Target samples and polyclonal-antibody-conjugated Au@Ag core-shell nanoparticles were then added. Using this SERS platform, the concentration of biomarkers could be quantified by monitoring the characteristic Raman peak intensity of Raman reporter molecules. Under optimized conditions, the limits of detection (LODs) were estimated to be 8.9 pg mL-1 and 9.7 pg mL-1 for cTnI and CK-MB, respectively. Thus, the proposed SERS-based immunoassay has great potential to be an effective diagnostic tool for the rapid and accurate detection of cTnI and CK-MB.

心肌肌钙蛋白 I (cTnI) 和肌酸激酶-MB (CK-MB) 是急性心肌梗死 (AMI) 的重要诊断生物标志物。人们付出了许多努力来开发高灵敏度的检测方法来定量分析这些双目标。然而，目前的免疫测定方法由于检测灵敏度有限，不足以准确测量 cTnI 和 CK-MB。因此，仍然迫切需要一种新技术来实现这些生物标志物的超高灵敏度检测。在本研究中，我们开发了一种基于表面增强拉曼散射 (SERS) 的夹心免疫分析平台，用于超灵敏检测 cTnI 和 CK-MB。在本研究中，单克隆抗体固定化金图案芯片被用作SERS活性模板。然后添加目标样品和多克隆抗体缀合的 Au@Ag 核壳纳米颗粒。使用该 SERS 平台，可以通过监测拉曼报告分子的特征拉曼峰强度来量化生物标志物的浓度。在优化条件下，cTnI 和 CK-MB 的检测限 (LOD) 估计分别为 8.9 pg mL-1 和 9.7 pg mL-1。因此，所提出的基于SERS的免疫测定法具有成为快速准确检测cTnI和CK-MB的有效诊断工具的巨大潜力。