title: Electrochemical impedance spectroscopy in label-free biosensor applications: multivariate data analysis for an objective interpretation.
abstract: Electrochemical impedance spectroscopy plays an important role in biosensor science thanks to the possibility of finding specific information from processes with different kinetics at a chosen electrode potential in one experiment. In this paper we briefly discuss label-free impedimetric biosensors described in the literature. A novel method for neutral interpretation of impedance data is presented that includes complex number chemometrics. Three examples are given based on impedance measurements on synthetic biomembranes, in this case a lipid monolayer deposited on a mercury electrode. The interaction of various compounds with the monomolecular lipid layer is illustrated with the following: (1) different concentrations of magainin (Geladi et al. in Proc. Int. Fed. Med. Biomed. Eng. 9:219-220, 2005); (2) different derivatives of gramicidin A (Lindholm-Sethson et al. in Langmuir 24:5029-5032, 2007), and (3) an antimicrobial peptide (Ringstad et al. in Langmuir 24:208-216, 2008).
authors.affiliation: Department of Chemistry, Umeå University, 901 87 Umeå, Sweden. britta.sethson@chem.umu.se
authors.forename: Britta
authors.initials: B
authors.lastname: Lindholm-Sethson
authors.forename: Josefina
authors.initials: J
authors.lastname: Nyström
authors.forename: Martin
authors.initials: M
authors.lastname: Malmsten
authors.forename: Lovisa
authors.initials: L
authors.lastname: Ringstad
authors.forename: Andrew
authors.initials: A
authors.lastname: Nelson
authors.forename: Paul
authors.initials: P
authors.lastname: Geladi
mesh_terms: D015374:Biosensing Techniques / Q000295:instrumentation / Q000379:methods* / Q000706:statistics & numerical data; D058266:Dielectric Spectroscopy / Q000295:instrumentation / Q000379:methods* / Q000706:statistics & numerical data; D015999:Multivariate Analysis