An Aptamer Biosensing Strategy for Label-Free Assay of Dual Acute Myocardial Infarction Biomarkers Built upon AuNPs/Ti3C2-MXenes

Abstract

The sensitive quantification of cardiac troponin I (cTnI) and myoglobin (Myo) in blood is essential for an early emergency diagnosis of acute myocardial infarction (AMI). Attributed to AuNPs and a titanium element on the surface of the AuNPs/Ti3C2-MXenes hybrid, each respective aptamer strand can be immobilized on. In this work, a nanohybrid was deposited on amino-functionalized indium tin oxide (ITO) via an Au–N bond; thereafter, it could catch cTnI-specific, thiol-functionalized DNA aptamer through Au–S self-assembly or Myo-aptamer via adsorption and metal chelate interaction between phosphate groups and titanium for specific recognition. Both using [Fe(CN)6]3−/4− as a signaling probe, the differential pulse voltammetric (DPV) current of the cTnI-aptasensor decreased after binding with cTnI, while the other responded to Myo via the impedimetric measurement. These developed biosensors enable the response to the femtogram/mL level cTnI or nanogram/mL level Myo. Remarkably, the proposed aptasensors exhibit high sensitivity and specificity for targets and display great potential for applications in clinic diagnosis.