State Key Laboratory of Pollution Control and Resources Reuse (Tongji University), College of Environmental Science and Engineering, Tongji University, Shanghai, 200092, China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai, 200092, China.
State Key Laboratory of Pollution Control and Resources Reuse (Tongji University), College of Environmental Science and Engineering, Tongji University, Shanghai, 200092, China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai, 200092, China.
Anal Chim Acta. 2024 Aug 15;1317:342866. doi: 10.1016/j.aca.2024.342866. Epub 2024 Jun 12.
Cardiac troponin I (CTnI) is demonstrated as one of the most promising disease biomarkers for early diagnosing acute myocardial infarction (AMI). To date, electrochemical immunosensors have been extensively studied in the field of cTnI determination. But highly accurate and sensitive cTnI detection by this method is still a challenge due to non-specific adsorption on electrode interfaces in complex human serum. As a result, it is necessary to develop an antifouling electrochemical immunosensor with high sensitivity for the detection of cTnI.
In this work, an antifouling electrochemical immunosensor was constructed based on vertically-aligned peptide layer consisting of Au nanoparticles (AuNPs) and amphiphilic CEAK16 peptide (CEAK16@AuNPs) for sensitive and accurate detection of cTnI in human serum. The vertically-aligned CEAK16@AuNPs interface provided a stable hydration layer originated from attraction of water molecules by amino acids on the hydrophilic side of the CEAK16, which effectively reduced non-specific adsorption and enhanced electron transfer rate. The cTnI immunosensor possessed great analytical performance with a wide range from 1 fg mL to 1 μg mL and a low detection limit of 0.28 fg mL (S/N = 3). Additionally, the proposed CEAK16@AuNPs sensing interface showed excellent long-term antifouling performance and electrochemical activity that preserved 80 % of the initial signal after 20-days exposure in human serum samples. Consequently, the cTnI immunosensor displayed excellent detection accuracy compared to clinical methods and owned good selectivity, stability and reproducibility.
The development of this strategy provides a versatile tool for accurate quantitative cTnI analysis in real human serum, thus helping to achieve early AMI diagnosis effectively and holding the promising potentials for other immunosensor in disease diagnosis.
心肌肌钙蛋白 I（cTnI）被证明是用于早期诊断急性心肌梗死（AMI）的最有前途的疾病生物标志物之一。迄今为止，电化学生物传感器已在 cTnI 测定领域得到了广泛研究。但是，由于在复杂的人血清中在电极界面上的非特异性吸附，该方法对 cTnI 的高度准确和灵敏的检测仍然是一个挑战。因此，有必要开发具有高灵敏度的用于检测 cTnI 的抗污染电化学生物传感器。
在这项工作中，构建了基于垂直排列的肽层的抗污染电化学生物传感器，该肽层由金纳米粒子（AuNPs）和两亲性 CEAK16 肽（CEAK16@AuNPs）组成，用于灵敏且准确地检测人血清中的 cTnI。垂直排列的 CEAK16@AuNPs 界面提供了源自亲水侧上的氨基酸吸引水分子的稳定水合层，这有效地减少了非特异性吸附并增强了电子转移速率。cTnI 免疫传感器具有从 1 fg mL 到 1 μg mL 的宽范围和低至 0.28 fg mL 的检测限（S/N = 3）的出色分析性能。此外，所提出的 CEAK16@AuNPs 传感界面表现出出色的长期抗污性能和电化学活性，在人血清样品中暴露 20 天后，其信号保持了初始信号的 80％。因此，与临床方法相比，cTnI 免疫传感器具有出色的检测准确性，并且具有良好的选择性，稳定性和重现性。
该策略的发展为在真实人血清中进行准确的定量 cTnI 分析提供了一种通用工具，从而有助于有效地实现早期 AMI 诊断，并为疾病诊断中的其他免疫传感器提供了有前途的潜力。
