Electrochemical Aptamer-Based Biosensors for the Detection ofCardiac Biomarkers

摘要

Rapid and accurate diagnostic technologies forearly-state identification of cardiovascular abnormalities havebecome of high importance to prevent and attenuate theirprogression. The capability of biosensors to determine anincrease in the concentration of cardiovascular proteinbiomarkers in circulating blood immediately after a myocardialinfarction makes them ideal point-of-care platforms andalternative approaches to electrocardiograms, chest X-rays,and different laboratory-based immunoassays. We report herea generic approach toward multianalyte sensing platforms forcardiac biomarkers by developing aptamer-based electrochemical sensors for brain natriuretic peptide (BNP-32) and cardiactroponin I (cTnI). For this, commercial gold-based screen-printed electrodes were modified electrophoretically withpolyethyleneimine/reduced graphene oxide films. Covalent grafting of propargylacetic acid integrates propargyl groups onto theelectrode to which azide-terminated aptamers can be immobilized using Cu(I)-based “click” chemistry. To ensure lowbiofouling and high specificity, cardiac sensors were modified with pyrene anchors carrying poly(ethylene glycol) units. In thecase of BNP-32, the sensor developed has a linear response from 1 pg mL?1 to 1 μg mL?1 in serum; for cTnI, linearity isobserved from 1 pg mL?1 to 10 ng mL?1 as demanded for early-stage diagnosis of heart failure. These electrochemicalaptasensors represent a step further toward multianalyte sensing of cardiac biomarkers.