Dual-Mode Electrochemical and Electrochemiluminescent Aptamer Biosensors for Point-of-Care Detection of Cardiac Troponin I
Mingxiang Liao, Zhuoliang Hu, Xilin Chen, Mengjie Chen, Zelin Yang, Jianbin Pan, Duanping Sun
Abstract
Acute myocardial infarction (AMI), a leading cause of global mortality, requires the rapid and accurate detection of cardiac troponin I (cTnI) for prompt intervention. To address this, we present an innovative dual-mode electrochemiluminescence–electrochemical (ECL–EC) aptasensor for point-of-care detection of cTnI. The platform employs Fe 3 O 4 /PEI/CdS quantum dots (QDs) (FePQ) functionalized with a Tro6 aptamer as ECL-active capture probes and ferrocene (Fc)-encapsulated UiO-66-NH 2 (UFc) conjugated with a Tro4 aptamer as dual-functional signal probes. Upon cTnI binding, a sandwich complex forms, enabling dual-signal transduction: ECL signal attenuation is achieved through energy transfer or electron transfer between FePQ and proximal UFc and enhanced square wave voltammetry (SWV) response from accumulated UFc moieties. This ECL–EC mechanism enables self-verification, significantly reducing false signals, while achieving a wide linear range from 0.001 to 100 ng/mL with low detection limits (0.49 and 0.74 pg/mL) for 60 min. Notably, the dual-mode detection system also demonstrates remarkable consistency for cTnI quantification in clinical samples. The integration of magnetic separation, aptamer-based recognition, and UiO-66-NH 2 -enhanced signal amplification ensures clinical practicality. The system demonstrates exceptional specificity, reproducibility, and stability in human serum analysis, not only providing a transformative solution for point-of-care AMI diagnostics but also establishing a versatile framework for developing multimodal biosensors targeting other biomarkers, advancing precision medicine in cardiovascular care.