title: Mediated amperometric immunosensing using single walled carbon nanotube forests.
abstract: A prototype amperometric immunosensor was evaluated based on the adsorption of antibodies onto perpendicularly oriented assemblies of single wall carbon nanotubes called SWNT forests. The forests were self-assembled from oxidatively shortened SWNTs onto Nafion/iron oxide coated pyrolytic graphite electrodes. The nanotube forests were characterized using atomic force microscopy and resonance Raman spectroscopy. Anti-biotin antibody strongly adsorbed to the SWNT forests. In the presence of a soluble mediator, the detection limit for horseradish peroxidase (HRP) labeled biotin was 2.5 pmol ml(-1) (2.5 nM). Unlabelled biotin was detected in a competitive approach with a detection limit of 16 nmol ml(-1) (16 microM) and a relative standard deviation of 12%. The immunosensor showed low non-specific adsorption of biotin-HRP (approx. 0.1%) when blocked with bovine serum albumin. This immunosensing approach using high surface area, patternable, conductive SWNT assemblies may eventually prove useful for nano-biosensing arrays.
authors.affiliation: National Centre for Sensor Research, Dublin City University, Dublin 9, Ireland.
authors.forename: Máire
authors.initials: M
authors.lastname: O'Connor
authors.forename: Sang Nyon
authors.initials: SN
authors.lastname: Kim
authors.forename: Anthony J
authors.initials: AJ
authors.lastname: Killard
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Forster
authors.forename: Malcolm R
authors.initials: MR
authors.lastname: Smyth
authors.forename: Fotios
authors.initials: F
authors.lastname: Papadimitrakopoulos
authors.forename: James F
authors.initials: JF
authors.lastname: Rusling
mesh_terms: D000327:Adsorption; D000818:Animals; D000906:Antibodies / Q000032:analysis*; D015374:Biosensing Techniques; D004563:Electrochemistry / Q000379:methods; D008832:Microchemistry / Q000295:instrumentation / Q000379:methods; D018625:Microscopy, Atomic Force; D037742:Nanotubes, Carbon; D013059:Spectrum Analysis, Raman
chemical_list: D000906:Antibodies; D037742:Nanotubes, Carbon