DNA hybridization enhancement in microarrays using AC-electrothermal flow

We present numerical and experimental results on an innovative method to enhance the hybridization process in the field of microarray based analytics. Hybridization reaction based on biochip approaches take several hours due to the fact that these reactions are diffusion limited. To monitor the binding of fluorescent labeled analyte molecules to the probe molecules on the chip surface we use a home made fluorescent detection system that allows continues monitoring of the reaction on chip. Mixing is the key to overcome the diffusion barrier and increase reaction rate. We present a novel mixing device that increases reaction time The AC-electrokinetic signal produces an electrothermal flow that enhances the DNA binding. We show an optimization of the AC-signal and the electrodes design based on numerical simulations to obtain highest efficiency in mixing of analyte solutions and we report experimental results on dephosphorylation experiment.