title: Optimization of nanowire DNA sensor sensitivity using self-consistent simulation.
abstract: In order to facilitate the rational design and the characterization of nanowire field-effect sensors, we have developed a model based on self-consistent charge-transport equations combined with interface conditions for the description of the biofunctionalized surface layer at the semiconductor/electrolyte interface. Crucial processes at the interface, such as the screening of the partial charges of the DNA strands and the influence of the angle of the DNA strands with respect to the nanowire, are computed by a Metropolis Monte Carlo algorithm for charged molecules at interfaces. In order to investigate the sensing mechanism of the device, we have computed the current–voltage characteristics, the electrostatic potential and the concentrations of electrons and holes. Very good agreement with measurements has been found and optimal device parameters have been identified. Our approach provides the capability to study the device sensitivity, which is of fundamental importance for reliable sensing.
authors.affiliation: Wolfgang Pauli Institute c/o Department of Mathematics, University of Vienna, A-1090 Vienna, Austria. Stefan.Baumgartner@univie.ac.at
authors.forename: S
authors.initials: S
authors.lastname: Baumgartner
authors.forename: M
authors.initials: M
authors.lastname: Vasicek
authors.forename: A
authors.initials: A
authors.lastname: Bulyha
authors.forename: C
authors.initials: C
authors.lastname: Heitzinger
mesh_terms: D000465:Algorithms; D015374:Biosensing Techniques / Q000295:instrumentation*; D003198:Computer Simulation; D004247:DNA / Q000032:analysis*; D004553:Electric Conductivity; D004583:Electrons; D004867:Equipment Design; D008956:Models, Chemical; D009010:Monte Carlo Method; D053770:Nanowires / Q000737:chemistry*; D012666:Semiconductors; D012680:Sensitivity and Specificity; D055672:Static Electricity
chemical_list: D004247:DNA