Significance: Cardiac troponin I (cTnI) is a primary biomarker for diagnosis of myocardial infarction (MI). In contrast to central laboratory tests for cTnI, point-of-care (POC) testing has the advantage of providing results when the patient is first encountered, which helps high-risk patients to be treated more rapidly and low-risk patients to be released in a timely fashion. A paper fluidic platform is good for POC testing because the paper is abundant, low cost, and disposable. However, current cTnI assays on paper platforms use antibodies as the recognition element, which has limitations due to the high cost of production and antibody stability issues at the POC. Aim: To develop an aptamer-based assay on a paper strip using surface-enhanced resonance Raman spectroscopy (SERRS) for detection of cTnI in the clinically relevant range at the POC. Approach: Gold nanoparticles (AuNPs) were functionalized with a Raman reporter molecule, malachite green isothiocyanate. The functionalized AuNPs were encapsulated in a silica shell and provided a SERRS signal using a handheld Raman system with a 638-nm excitation wavelength. A primary aptamer and a secondary aptamer of cTnI were used in a sandwich assay format to bind the cTnI on a test line of a paper fluidic platform. By measuring the SERRS signal from the test line, the concentration of cTnI was quantitatively determined. Results: The aptamer-based SERRS assay on a paper strip had a detection range of 0.016 to 0.1 ng / ml for cTnI, had good selectivity for cTnI compared to three other markers, had good stability over 10 days, and had good performance in the more complex serum sample matrix. Conclusions: The aptamer-based SERRS assay on a paper strip has the potential to provide a sensitive, selective, stable, repeatable, and cost-effective platform for the detection of cTnI toward eventual use in diagnosis of MI at the POC.

中文翻译：

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在纸流体平台上进行基于适体的表面增强共振拉曼散射测定，用于检测心肌肌钙蛋白 I。


意义：心肌肌钙蛋白 I (cTnI) 是诊断心肌梗死 (MI) 的主要生物标志物。与 cTnI 的中心实验室检测相比，即时检测 (POC) 检测的优点是可以在第一次接触患者时提供结果，这有助于高风险患者得到更快的治疗，并帮助低风险患者出院及时。纸质流体平台非常适合 POC 测试，因为纸质丰富、成本低且一次性。然而，目前纸质平台上的 cTnI 检测使用抗体作为识别元件，由于生产成本高和 POC 抗体稳定性问题而存在局限性。目的：使用表面增强共振拉曼光谱 (SERRS) 在纸条上开发一种基于适配体的检测方法，用于在 POC 中检测临床相关范围内的 cTnI。方法：金纳米颗粒 (AuNP) 使用拉曼报告分子孔雀石绿异硫氰酸酯进行功能化。将功能化的 AuNP 封装在二氧化硅壳中，并使用激发波长为 638 nm 的手持式拉曼系统提供 SERRS 信号。 cTnI 的初级适体和次级适体以夹心测定形式使用，以将 cTnI 结合在纸流体平台的测试线上。通过测量测试线的 SERRS 信号，定量测定 cTnI 的浓度。结果：基于适配体的纸条 SERRS 检测对 cTnI 的检测范围为 0.016 至 0.1 ng/ml，与其他三种标记物相比，对 cTnI 具有良好的选择性，在 10 天内具有良好的稳定性，并且在检测中具有良好的性能。更复杂的血清样品基质。 结论：基于适体的纸条 SERRS 检测有可能为 cTnI 检测提供灵敏、选择性、稳定、可重复且经济高效的平台，最终用于 POC 诊断 MI。