The development of highly sensitive and specific method for the detection of cardiac troponin I (cTnI) is of great importance for the early diagnosis and prognosis of myocardial injury. Herein, a sandwich signal-on biosensor for cTnI has been developed through antibody-cTnI-aptamer sandwiched structure using a metal-organic framework (MOF) of Fe(III)-2-amino terephthalic acid (Fe-ATA) as a bifunctional nanocarrier for the loading of signal molecule of dopamine and recognition element of aptamer. The cTnI antibody was first immobilized on electro synthesized gold nanoparticles (AuNPs) modified electrode. Through the immunoreaction, the target cTnI was captured onto the electrode surface, followed by the binding of the Fe-ATA MOF via aptamer chemistry. Thanks to dual signal amplification that provided by high electroconductivity of AuNPs and the large surface area of Fe-ATA for loading numerous signal molecules, the biosensor presents an outperformed analytical performance for cTnI with a wide kinetic range from 10 fg mL to 100 ng mL and an ultralow detection limit of 0.92 fg mL. The spiked recovery assay shows that the proposed method is reliable for the detection of cTnI in actual human serum sample.

中文翻译：

---

合理利用Fe(III)-2-氨基对苯二甲酸MOF作为多巴胺和适配体双功能纳米载体构建心肌肌钙蛋白I超灵敏夹心生物传感器

发展高灵敏、特异的心肌肌钙蛋白I（cTnI）检测方法对于心肌损伤的早期诊断和预后判断具有重要意义。在此，利用Fe(III)-2-氨基对苯二甲酸(Fe-ATA)的金属有机框架(MOF)作为双功能纳米载体，通过抗体-cTnI-适体夹层结构开发了cTnI夹心信号生物传感器用于装载多巴胺信号分子和适体识别元件。 cTnI 抗体首先固定在电合成金纳米颗粒 (AuNPs) 修饰的电极上。通过免疫反应，目标 cTnI 被捕获到电极表面，然后通过适体化学与 Fe-ATA MOF 结合。由于 AuNPs 的高导电性和 Fe-ATA 的大表面积（用于加载大量信号分子）提供的双重信号放大，该生物传感器对 cTnI 具有出色的分析性能，具有从 10 fg mL 到 100 ng mL 的宽动力学范围，并且0.92 fg mL 的超低检测限。加标回收率测定表明，该方法对于实际人血清样品中 cTnI 的检测是可靠的。