High-Throughput Dielectrophoretic Trapping and Detection of DNA Origami

Abstract

Accurate control over the location of nanostructured materials for studying their electronic properties is important for the development of useful electronic devices. Dielectrophoresis is a unique method for trapping non-symmetric nanostructured materials between two electrodes in a specific direction. However, this method has traditionally suffered from a costly and slow fabrication process as well as low efficiency when trapping high-impedance nanomaterials. In this work, a dielectrophoretic device addressing the mentioned problems, is reported. First, a photolithography-based fabrication process achieves high throughput and low-cost devices with nanostructured contacts for attaching nanomaterials. Second, trapping of high-impedance nanomaterials is controlled using a scalable-electronic circuit that measures the capacitance variation at the trap location to identify when the nanomaterials of interest are attached to the electrode. As a primary target of interest, the trapping of 1D deoxyribonucleic acid (DNA) origamis is demonstrated. It is shown that a capacitance change in the range of 18% to 60% guarantees the presence of a single or a few DNA origamis in the trap location well-aligned with nanoelectrodes. Fluorescent, scanning electron microscopy, and atomic force microscopy images demonstrate the presence of DNA origamis in the trap location with the correct orientation.