title: Electrochemical analysis of HIV-1 reverse transcriptase serum level: exploiting protein binding to a functionalized nanostructured surface.
abstract: This manuscript describes an electrochemical approach to the detection of the reverse transcriptase of the human immunodeficiency virus type-1 (HIV-1 RT) in serum exploiting an organometallic peptide conjugate that is chemically linked to a nanostructured gold surface. The assay format is based on the formation of a thin film of a ferrocene-labeled lipoic acid (Fc-LA) onto a gold nanoparticles-functionalized screen-printed carbon electrode (GNPs-SPCE). Time-of-Flight secondary ion mass spectrometry (TOF-SIMS) and X-ray photoelectron spectroscopy were employed to confirm the binding of the Fc-LA to the electrode surface via formation of a gold-thiol bond. The RT biosensor was developed by covalent attachment of the peptide VEAIIRILQQLLFIH to the carboxylic acid group of Fc-LA. Square wave voltammetry offered a two-dimensional measurement of RT based on the anodic shift and reduction of current density of the Fc redox signal upon binding of RT to its specific peptide. This allowed a linear quantification of the target RT in the range of 1-500 pg mL(-1) equivalent to 0.9-427 fM, with a detection limit of 0.8 pg mL(-1) (0.7 fM) with a short response time.
authors.affiliation: Department of Chemistry, University of Western Ontario, 1151 Richmond Street, London, ON, Canada N6A 5B7.
authors.forename: Mahmoud
authors.initials: M
authors.lastname: Labib
authors.forename: Sanela
authors.initials: S
authors.lastname: Martić
authors.forename: Patrick O
authors.initials: PO
authors.lastname: Shipman
authors.forename: Heinz-Bernhard
authors.initials: HB
authors.lastname: Kraatz
mesh_terms: D015374:Biosensing Techniques / Q000379:methods*; D055664:Electrochemical Techniques / Q000379:methods*; D005296:Ferrous Compounds; D054303:HIV Reverse Transcriptase / Q000097:blood*; D006801:Humans; D057230:Limit of Detection; D000075163:Metallocenes; D049329:Nanostructures / Q000737:chemistry*; D010455:Peptides; D011485:Protein Binding; D008063:Thioctic Acid
chemical_list: D005296:Ferrous Compounds; D000075163:Metallocenes; D010455:Peptides; D008063:Thioctic Acid; C514824:reverse transcriptase, Human immunodeficiency virus 1; D054303:HIV Reverse Transcriptase; C004998:ferrocene