title: Picomolar detection of protease using peptide/single walled carbon nanotube/gold nanoparticle-modified electrode.
abstract: 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.
authors.affiliation: Biotechnology Research Institute, National Research Council Canada, Montreal, Canada H4P2R2.
authors.forename: Khaled A
authors.initials: KA
authors.lastname: Mahmoud
authors.forename: Sabahudin
authors.initials: S
authors.lastname: Hrapovic
authors.forename: John H T
authors.initials: JH
authors.lastname: Luong
mesh_terms: D015374:Biosensing Techniques / Q000295:instrumentation*; D004563:Electrochemistry / Q000295:instrumentation / Q000379:methods*; D006046:Gold / Q000737:chemistry*; D016333:HIV Protease / Q000032:analysis* / Q000737:chemistry; D046911:Macromolecular Substances / Q000737:chemistry; D008422:Materials Testing; D008832:Microchemistry / Q000295:instrumentation / Q000379:methods; D008839:Microelectrodes; D008968:Molecular Conformation; D036103:Nanotechnology / Q000295:instrumentation* / Q000379:methods; D037742:Nanotubes, Carbon / Q000737:chemistry* / Q000648:ultrastructure; D010455:Peptides / Q000737:chemistry; D013499:Surface Properties
chemical_list: D046911:Macromolecular Substances; D037742:Nanotubes, Carbon; D010455:Peptides; D006046:Gold; D016333:HIV Protease