Label-free electrochemiluminescence aptasensor for rapid and accurate detection of cardiac troponin I.

Acute myocardial infarction (AMI) is the most common cause of death in individuals with cardiovascular disease. Cardiac troponin I (cTnI) is acknowledged as the most prominent biomarker for AMI. However, the key problem of practical applications is how to effectively improve the detection speed and sensitivity. In this study, we designed a novel electrochemiluminescence (ECL) aptasensor for the rapid and quantitative determination of cTnI. This sensor employs self-luminous europium-based metal-organic framework@CdS quantum dots (Eu-MOF@CdS QDs) as a signal probe. The Eu-MOF@CdS QDs can produce a robust cathodic ECL signal via a synergistic effect. Furthermore, a ferrocene-labeled aptamer was used as a quenching probe for quenching the ECL emission of the Eu-MOF@CdS QDs. In the presence of cTnI, the ECL intensity increased with increasing cTnI concentration after ferrocene-labeled aptamer specifically recognized cTnI and was detached from the electrode interface. Under optimal conditions, the aptasensor demonstrated precise analytical capabilities for cTnI ranging from 1.0 pg/mL to 1.0 ng/mL with a notably low detection limit of 0.08 pg/mL within 60 min. The results show that the developed ECL sensing device demonstrates the potential applications and perspectives for the detection of cTnI in serum samples as well as in the field of biomedical analyses.