Barton, Andrew C.Collyer, Stuart D.Davis, FrankGarifallou, Goulielmos-ZoisTsekenis, GeorgiosTully, ElizabethO'Kennedy, RichardGibson, TimMillner, Paul A.Higson, Seamus P. J.2011-10-112011-10-112009-01-01Andrew C. Barton, Stuart D. Collyer, Frank Davis, Goulielmos-Zois Garifallou, Georgios Tsekenis, Elizabeth Tully, Richard O'Kennedy, Tim Gibson, Paul A. Millner, Seamus P.J. Higson, Labeless AC impedimetric antibody-based sensors with pg ml-1 sensitivities for point-of-care biomedical applications, Biosensors and Bioelectronics, Volume 24, Issue 5, Selected Papers from the Tenth World Congress on Biosensors Shangai, China, May 14-16, 2008, 1 January 2009, Pages 1090-10950956-5663http://dx.doi.org/10.1016/j.bios.2008.06.001http://dspace.lib.cranfield.ac.uk/handle/1826/3196This paper describes the development and characterisation of labeless immunosensors for (a) the cardiac drug digoxin and (b) bovine serum albumin (BSA). Commercial screen-printed carbon electrodes were used as the basis for the sensors. Two methods were used to immobilise antibodies at the electrode surface. Aniline was electropolymerised onto these electrodes to form a thin planar film of conductive polyaniline; the polyaniline film was then utilised as a substrate to immobilise biotinylated anti-digoxin using a classical avidin- biotin affinity approach. As an alternative approach, poly(1,2-diaminobenzene) was electrodeposited onto the carbon electrodes and this modified surface was then sonochemically ablated to form an array of micropores. A second electropolymerisation step was then used to co-deposit conductive polyaniline along with antibodies for BSA within these pores to produce a microarray of polyaniline protrusions with diameters of several μm, containing entrapped anti- BSAen-UKAC impedanceImmunosensorPolyanilineMicroelectrodeBSADigoxinArticle