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.

Three‐Dimensional Interdigitated Electrode Array as a Tool for Surface Reactions Registration

“…The impedance response of an IDEA device in low conductivity solutions in the absence of faradaic processes may be emulated by an electrical equivalent [12] circuit presented in Scheme 1A. It is formed by the following components: R C is the contact resistance introduced by wires and collector bars of the electrodes; C G is the geometrical capacitance between two interdigitated electrodes in a water solution; R S is the resistance of the water solution between two electrodes of the array; and CPE DL , which is a constant phase element associated with the capacitance of the electrical double layer at the electrodewater solution interface.…”

A contactless electrical stimulator: application to fabricate functional skeletal muscle tissue

“…Following an initial denaturation step at 95°C for 10 min, real time PCR was performed over 45 cycles of 95°C for 10 s, 62°C for 10 s, and 72°C for 20 s, followed by a melt curve analysis. The expression of the target gene was assessed using the comparative method (Berdat et al 2008), and the results were normalized to the mouse GAPDH gene as the internal reference.…”

Application of thin metal film elements in bioanalysis

“…DNA probe was bound on the glass between the electrodes and conductance was measured after hybridization with target sequence. The system was tested to detect pathogen DNA samples from Salmonella choleraesuis in dairy food and enabled detection of unlabeled DNA down to concentrations of interest for food quality control [51].…”