DNA Network Construction by Optically Induced Dielectrophoresis

In this work, an optically induced dielectrophoretic force field was used in manipulating deoxyribonucleic acid (DNA), and a DNA network was formed at the position of virtual electrode which was observed by atomic force microscope (AFM). The amorphous hydrogenated silicon (a-Si:H) film was used to structure the virtual electrodes when a beam of light from a projector was illuminated into it and the illuminated area became conductive. The mica was used as the substrate of DNA and placed between the two ITO electrodes. An AC electric field of 2 V peakto-peak at 50 kHz was used across the electrodes. The mica substrate with DNA solution was naturally air dry after functioned with the optically induced dielectrophoresis (ODEP) force and scanned by AFM. The results show that DNA was attracted by positive dielectrophoretic force and converged at the position of virtual electrode, and the overall shape and the specific position of DNA network on substrate could be controlled by changing the virtual electrode shape and position. The average height of the DNA networks was close to the real height of DNA, which was helpful for analyzing the DNA network electrical conductivity. This work has proven that the ODEP can be used as the tool to manipulate DNA and structure DNA molecular devices.