Electrochemical Aptamer-Based Biosensors for the Detection of Cardiac Biomarkers

Abstract

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 were modified with pyrene anchors carrying poly(ethylene glycol) units. In the case 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 is observed from 1 pg mL–1 to 10 ng mL–1 as demanded for early-stage diagnosis of heart failure. These electrochemical aptasensors represent a step further toward multianalyte sensing of cardiac biomarkers.

An electrochemical aptamer-based sensor for the rapid and convenient measurement of l-tryptophan

“…To this end, the miniaturazibility of E-AB sensors and potential cost-effectiveness of E-AB sensors are also significant advantages. For example, exploiting screen-printed electrodes [29], it could be possible to adapt E-AB sensors on disposable strips read by a small portable potentiostat. At the same time, the development of a user-friendly interface could help patients converting the analytical signal into useful clinical data, for example, creating a specific application for the mobile phone.…”

Applications of Graphene Quantum Dots in Biomedical Sensors

“…These sensors integrate a biological element with a physiochemical transducer to generate an electronic signal, which is directly proportional to the analyte concentration and subsequently conveyed to a detector [12]. Generally, the classification of biosensors depends on: (a) the type of receptors employed during the bio-recognition events, such as antibody [13], peptide [14], enzyme [15,16] aptamer [17], DNA [18] and molecularly imprinted polymer (MIP)-based sensors [19,20]; (b) the type of transducers involved, such as electrochemical [21], optical [22], piezoelectric [23] and calorimetric biosensors [24]. They can accomplish the requirements of rapid and specific sensing of the biomolecules as well as the real-time analysis of modern detection techniques.…”

Antibodies, Nanobodies, or Aptamers—Which Is Best for Deciphering the Proteomes of Non-Model Species?

“…For example, transport needs to be refrigerated and antibodies/nanobodies need to be kept cool to ensure they remain functional, whereas aptamers are stable at higher temperatures [53,100]. Additionally, while aptamers have been used to replace antibodies in typical laboratory tests, they have also come into their own in a number of in vitro diagnostic assays that would be easily adapted to in field or POCT [101][102][103][104].…”