title: Label-free detection of DNA with interdigitated micro-electrodes in a fluidic cell.
abstract: We investigate the analytical performance of an interdigitated electrode sensor for the label-free detection of DNA, by monitoring the complex impedance of 5 microm wide interdigitated Pt microelectrodes on a glass substrate. We detect the hybridization of unlabeled 38-mer target ssDNA with a complementary probe that is bound on the glass in between the electrodes by a disuccinimidyl terephtalate and aminosilane immobilization procedure. The sensor is mounted in a microfluidic flow cell, in which hybridization is monitored and in situ compared with a reference. After hybridization, the cell is perfused with deionised water and the dependence of the measured conductance due to the immobilized target DNA layer, to target DNA concentrations down to 1 nM is demonstrated. Subsequently, we apply our sensor to the detection of pathogen DNA from Salmonella choleraesuis in dairy food.
authors.affiliation: Institute of Microelectronics and Microsystems, Ecole Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland.
authors.forename: Daniel
authors.initials: D
authors.lastname: Berdat
authors.forename: Ana C
authors.initials: AC
authors.lastname: Martin Rodríguez
authors.forename: Fernando
authors.initials: F
authors.lastname: Herrera
authors.forename: Martin A M
authors.initials: MA
authors.lastname: Gijs
mesh_terms: D015374:Biosensing Techniques / Q000295:instrumentation / Q000379:methods*; D004247:DNA / Q000032:analysis*; D008839:Microelectrodes; D046210:Microfluidic Analytical Techniques / Q000295:instrumentation / Q000379:methods*; D010984:Platinum / Q000737:chemistry*; D012680:Sensitivity and Specificity
chemical_list: D010984:Platinum; D004247:DNA