Electrochemical Aptamer-Based Biosensors for the Detectionof Cardiac Biomarkers

摘要

Rapid and accurate diagnostic technologies for early-state identification of cardiovascular abnormalities have become of high importance to prevent and attenuate their progression. The capability of biosensors to determine an increase in the concentration of cardiovascular protein biomarkers in circulating blood immediately after a myocardial infarction makes them ideal point-of-care platforms and alternative approaches to electrocardiograms, chest X-rays, and different laboratory-based immunoassays. We report here a generic approach toward multianalyte sensing platforms for cardiac biomarkers by developing aptamer-based electrochemical sensors for brain natriuretic peptide (BNP-32) and cardiac troponin I (cTnI). For this, commercial gold-based screen-printed electrodes were modified electrophoretically with polyethyleneimine/reduced graphene oxide films. Covalent grafting of propargylacetic acid integrates propargyl groups onto the electrode to which azide-terminated aptamers can be immobilized using Cu(I)-based “click” chemistry. To ensure low biofouling and high specificity, cardiac sensors weremodified with pyrene anchors carrying poly(ethylene glycol) units.In the case of BNP-32, the sensor developed has a linear responsefrom 1 pg mL^–1 to 1 μg mL^–1 in serum; for cTnI, linearity is observed from 1 pg mL^–1 to 10 ng mL^–1 as demanded for early-stage diagnosisof heart failure. These electrochemical aptasensors represent a stepfurther toward multianalyte sensing of cardiac biomarkers.