Skip to Content
Merck
  • Label-Free, Highly Sensitive Electrochemical Aptasensors Using Polymer-Modified Reduced Graphene Oxide for Cardiac Biomarker Detection.

Label-Free, Highly Sensitive Electrochemical Aptasensors Using Polymer-Modified Reduced Graphene Oxide for Cardiac Biomarker Detection.

ACS omega (2020-03-10)
Abhinav Sharma, Jyoti Bhardwaj, Jaesung Jang
ABSTRACT

Acute myocardial infarction (AMI), also recognized as a "heart attack," is one leading cause of death globally, and cardiac myoglobin (cMb), an important cardiac biomarker, is used for the early assessment of AMI. This paper presents an ultrasensitive, label-free electrochemical aptamer-based sensor (aptasensor) for cMb detection using polyethylenimine (PEI)-functionalized reduced graphene oxide (PEI-rGO) thin films. PEI, a cationic polymer, was used as a reducing agent for graphene oxide (GO), providing highly positive charges on the rGO surface and allowing direct immobilization of negatively charged single-strand DNA aptamers against cMb via electrostatic interaction without any linker or coupling chemistry. The presence of cMb was detected on Mb aptamer-modified electrodes using differential pulse voltammetry via measuring the current change due to the direct electron transfer between the electrodes and cMb proteins (Fe3+/Fe2+). The limits of detection were 0.97 pg mL-1 (phosphate-buffered saline) and 2.1 pg mL-1 (10-fold-diluted human serum), with a linear behavior with logarithmic cMb concentration. The specificity and reproducibility of the aptasensors were also examined. This electrochemical aptasensor using polymer-modified rGO shows potential for the early assessment of cMb in point-of-care testing applications.

MATERIALS
Product Number
Brand
Product Description

Sigma-Aldrich
Bovine Serum Albumin, lyophilized powder, ≥96% (agarose gel electrophoresis)
Sigma-Aldrich
Hydrochloric acid, 36.5-38.0%, BioReagent, for molecular biology
Sigma-Aldrich
Sulfuric acid, 99.999%
Sigma-Aldrich
Chloroacetic acid, 99%
Sigma-Aldrich
Sodium nitrate, ReagentPlus®, ≥99.0%
Sigma-Aldrich
Graphite, powder, <20 μm, synthetic
Sigma-Aldrich
Hydrogen peroxide solution, contains inhibitor, 30 wt. % in H2O, ACS reagent
Sigma-Aldrich
Potassium permanganate, ACS reagent, ≥99.0%
Sigma-Aldrich
Myoglobin from equine skeletal muscle, 95-100%, essentially salt-free, lyophilized powder