Electrochemical ELISA Protein Biosensing in Undiluted Serum Using a Polypyrrole-Based Platform

Sunil Arya, Pedro Estrela

Research output: Contribution to journalLetterpeer-review

10 Citations (SciVal)
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An electrochemical enzyme-linked immunosorbent assay (ELISA) biosensor platform using electrochemically prepared ~11 nm thick carboxylic functionalized popypyrrole film has been developed for bio-analyte measurement in undiluted serum. Carboxyl polypyrrole (PPy-COOH) film using 3-carboxy-pyrrol monomer onto comb-shaped gold electrode microarray (Au) was prepared via cyclic voltammetry (CV). The prepared Au/PPy-COOH was then utilized for electrochemical ELISA platform development by immobilizing analyte-specific antibodies. Tumor necrosis factor-alpha (TNF-α) was selected as a model analyte and detected in undiluted serum. For enhanced performance, the use of a polymeric alkaline phosphatase tag was investigated for the electrochemical ELISA. The developed platform was characterized at each step of fabrication using CV, electrochemical impedance spectroscopy and atomic force microscopy. The bioelectrodes exhibited linearity for TNF-α in the 100 pg/mL–100 ng/mL range when measured in spiked serum, with limit of detection of 78 pg/mL. The sensor showed insignificant signal disturbance from serum proteins and other biologically important proteins. The developed platform was found to be fast and specific and can be applicable for testing and measuring various biologically important protein markers in real samples.
Original languageEnglish
Article number2857
Number of pages13
Issue number10
Publication statusPublished - 18 May 2020

Bibliographical note

Funding Information:
Funding: This research was funded by the European Commission Horizon 2020 Programme through a Marie Skłodowska-Curie Individual Fellowship (grant no. 655176, 2015-2017).

Publisher Copyright:
© 2020 by the authors. Licensee MDPI, Basel, Switzerland.


  • Biomarker
  • Biosensor
  • Carboxyl polypyrrole
  • Differential pulse voltammetry
  • Electrochemical ELISA
  • Polymeric alkaline phosphatase
  • TNF-α

ASJC Scopus subject areas

  • Analytical Chemistry
  • Biochemistry
  • Atomic and Molecular Physics, and Optics
  • Instrumentation
  • Electrical and Electronic Engineering


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