title: Predicting and rationalizing the effect of surface charge distribution and orientation on nano-wire based FET bio-sensors.
abstract: A single charge screening model of surface charge sensors in liquids (De Vico et al., Nanoscale, 2011, 3, 706-717) is extended to multiple charges to model the effect of the charge distributions of analyte proteins on FET sensor response. With this model we show that counter-intuitive signal changes (e.g. a positive signal change due to a net positive protein binding to a p-type conductor) can occur for certain combinations of charge distributions and Debye lengths. The new method is applied to interpret published experimental data on Streptavidin (Ishikawa et al., ACS Nano, 2009, 3, 3969-3976) and Nucleocapsid protein (Ishikawa et al., ACS Nano, 2009, 3, 1219-1224).
authors.affiliation: Department of Chemistry, University of Copenhagen, Universitetsparken 5, DK-2100, Copenhagen, Denmark. luca@chem.ku.dk
authors.forename: Luca
authors.initials: L
authors.lastname: De Vico
authors.forename: Lars
authors.initials: L
authors.lastname: Iversen
authors.forename: Martin H
authors.initials: MH
authors.lastname: Sørensen
authors.forename: Mads
authors.initials: M
authors.lastname: Brandbyge
authors.forename: Jesper
authors.initials: J
authors.lastname: Nygård
authors.forename: Karen L
authors.initials: KL
authors.lastname: Martinez
authors.forename: Jan H
authors.initials: JH
authors.lastname: Jensen
mesh_terms: D015374:Biosensing Techniques; D036022:Capsid Proteins / Q000737:chemistry / Q000378:metabolism; D007204:Indium / Q000737:chemistry; D053770:Nanowires / Q000737:chemistry*; D011485:Protein Binding; D055672:Static Electricity; D019809:Streptavidin / Q000737:chemistry / Q000378:metabolism; D014173:Transistors, Electronic
chemical_list: D036022:Capsid Proteins; D007204:Indium; C047711:indium oxide; D019809:Streptavidin