Picomolar detection of protease using peptide/single walled carbon nanotube/gold nanoparticle-modified electrode

Khaled Mahmoud, Sabahudin Hrapovic, John H T Luong

Research output: Contribution to journalArticle

102 Citations (Scopus)


Picomolar electrochemical detection of human immunodeficiency virus type-1 protease (HIV-1 PR) using ferrocene (Fc)-pepstatin-modified surfaces has been presented. Gold electrode surface was modified with gold nanoparticles (AuNP) or thiolated single walled carbon nanotubes/ gold nanoparticles (SWCNT/AuNP). Thiol-terminated Fc-pepstatin was then self-assembled on such surfaces as confirmed by Raman spectroscopy and scanning electron microscope. The interaction between the Fc-pepstatin-modified substrates and HIV-1 PR was studied by cyclic voltammetry and electrochemical impedance spectroscopy. Both electrode materials showed enhanced electrochemical responses to increasing concentrations of HIV-1 PR with shifting to higher potentials as well as decrease in the overall signal intensity. However, the sensing electrode modified with thiolated SWCNTs/AuNPs showed remarkable detection sensitivity with an estimated detection limit of 0.8 pM.

Original languageEnglish
Pages (from-to)1051-1057
Number of pages7
JournalACS Nano
Issue number5
Publication statusPublished - 1 May 2008
Externally publishedYes



  • Biosensor
  • Carbon nanotubes
  • Ferrocene-pepstatin inhibitor
  • Gold nanoparticles
  • Protease

ASJC Scopus subject areas

  • Engineering(all)
  • Materials Science(all)
  • Physics and Astronomy(all)

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