Hybridization chain reaction-enhanced electrochemically mediated ATRP coupling high-efficient magnetic separation for electrochemical aptasensing of cardiac troponin I

• Published in: Analytica chimica acta Vol. 1286; p. 342034
• Main Authors: Peng, Xiaolun, He, Rongxiang, Xu, Junhui, Cao, Chunhua, Wen, Wei, Zhang, Xiuhua, Wang, Shengfu
• Format: Journal Article
• Language: English
• Published: 15.01.2024
• ISSN: 0003-2670; 1873-4324
• DOI: 10.1016/j.aca.2023.342034

The sensitive and accurate detection of cardiac troponin I (cTnI) as a gold biomarker for cardiovascular diseases at an early stage is crucial but has long been a challenge. In this study, we presented such an electrochemical (EC) aptasensor by combining hybridization chain reaction (HCR)-enhanced electrochemically mediated atom transfer radical polymerization (eATRP) amplification with high-efficient separation of magnetic beads (MBs). Aptamer-modified MBs empowered effective recognition and separation of cTnI from complex samples with high specificity. The specific binding of cTnI and aptamer could release triggered DNA (T-DNA) into solution to drive an HCR process, which produced plentiful active sites for eATRP initiators labeling followed by initiating eATRP process. With the development of eATRP, a great many of electroactive polymer probes were continually in situ formed to generate amplified current output for signal enhancement. Compared to no amplification, HCR-enhanced eATRP promoted the signals by ∼10-fold, greatly improving detection sensitivity for low-abundant cTnI analysis. Integrating MBs as capture carriers with HCR-enhanced eATRP as amplification strategy, this EC aptasensor achieved a low detection limit of 10.9 fg/mL for cTnI detection. Furthermore, the reliable detectability and anti-interference were confirmed in serum samples, indicating its promising application toward early diagnosis of cardiovascular diseases.