Antibody coated conductive polymer for the electrochemical immunosensing of Human Cardiac Troponin I in blood plasma

Mahnaz D Gholami; Anthony P O'Mullane; Prashant Sonar; Godwin A Ayoko; Emad L Izake

doi:10.1016/j.aca.2021.339082

Antibody coated conductive polymer for the electrochemical immunosensing of Human Cardiac Troponin I in blood plasma

Anal Chim Acta. 2021 Nov 15:1185:339082. doi: 10.1016/j.aca.2021.339082. Epub 2021 Sep 20.

Authors

Mahnaz D Gholami¹, Anthony P O'Mullane², Prashant Sonar³, Godwin A Ayoko³, Emad L Izake⁴

Affiliations

¹ School of Chemistry and Physics, Faculty of Science, Queensland University of Technology (QUT), 2 George Street, Brisbane, QLD, 4000, Australia.
² School of Chemistry and Physics, Faculty of Science, Queensland University of Technology (QUT), 2 George Street, Brisbane, QLD, 4000, Australia; Centre for Materials Science, Queensland University of Technology (QUT), 2 George Street, Brisbane, QLD, 4000, Australia. Electronic address: anthony.omullane@qut.edu.au.
³ School of Chemistry and Physics, Faculty of Science, Queensland University of Technology (QUT), 2 George Street, Brisbane, QLD, 4000, Australia; Centre for Materials Science, Queensland University of Technology (QUT), 2 George Street, Brisbane, QLD, 4000, Australia.
⁴ School of Chemistry and Physics, Faculty of Science, Queensland University of Technology (QUT), 2 George Street, Brisbane, QLD, 4000, Australia; Centre for Materials Science, Queensland University of Technology (QUT), 2 George Street, Brisbane, QLD, 4000, Australia. Electronic address: e.kiriakous@qut.edu.au.

PMID: 34711328
DOI: 10.1016/j.aca.2021.339082

Abstract

Cardiac troponin I (cTnI) is a sensitive biomarker for cardiovascular disease (CVD). Rapid determination of cTnI concentration in blood can greatly reduce the potential of significant heart damage and heart failure. Herein, we demonstrate a new electrochemical immunosensor for selective affinity binding and rapid detection of cTnI in blood plasma by an electrochemical method. A conductive film of "poly 2,5-bis(2-thienyl)3,4-diamine-terthiophene (PDATT)" was deposited onto an Indium Tin Oxide (ITO) electrode using chronoamperometry. Anti-cardiac troponin I antibody was then attached to the two amine (NH₂) groups substituted on the central thiophene of terthiophene repeating unit of the polymer chain via amide bond formation. The gaps on the surface of the antibody coated immunosensor were backfilled with bovine serum albumin (BSA) to prevent nonspecific binding of interfering molecules. Differential pulse voltammetry (DPV) was used to determine cTnI upon the formation of cTnI immunocomplex on the sensing surface, appearing a peak at 0.27 V. The response range was 0.01-100 ng mL^-1 with limit of quantification down to 0.01 ng mL^-1. The developed immunosensor was used to determine cTnI in spiked blood plasma without interference from cardiac troponin T (cTnT). Therefore, this new sensor can be utilised for the detection of cTnI biomarker in pathological laboratories and points of care in less than 15 min.

Keywords: Cardiac troponin I; Cardiovascular disease; Immunosensor; PDATT.

MeSH terms

Antibodies, Immobilized
Biosensing Techniques*
Electrochemical Techniques
Humans
Immunoassay
Limit of Detection
Plasma
Polymers
Troponin I*
Troponin T

Substances

Antibodies, Immobilized
Polymers
Troponin I
Troponin T