title: An immunological interleukine-6 capacitive biosensor using perturbation with a potentiostatic step.
abstract: An instrument for potentiostatic capacitance measurements, based on perturbation with a potentiostatic step was used. The capacitive sensor consisted of self-assembled sulfur compounds on gold to which antibodies towards Interleukine 6, Il-6, had been immobilized. The biosensor was part of a potentiostatic three-electrode system with an extra reference electrode. Two different methods using epoxy- or carbodiimide coupling of the polyclonal antibodies were compared. The antigen Il-6 could be detected from 5 x 10(-16) to 5 x 10(-13) M with one immobilization method and to more than 5 x 10(-9) M with the other. No labels were necessary since the binding of the antigen was detected directly. The insulating properties of the different layers of the biosensor were investigated.
authors.affiliation: Department of Analytical Chemistry, University of Lund, Sweden.
authors.forename: C
authors.initials: C
authors.lastname: Berggren
authors.forename: B
authors.initials: B
authors.lastname: Bjarnason
authors.forename: G
authors.initials: G
authors.lastname: Johansson
mesh_terms: D015374:Biosensing Techniques; D004553:Electric Conductivity; D004573:Electrolytes / Q000032:analysis; D004579:Electron Transport; D006046:Gold; D007158:Immunologic Techniques; D015850:Interleukin-6 / Q000032:analysis*; D011199:Potentiometry
chemical_list: D004573:Electrolytes; D015850:Interleukin-6; D006046:Gold