Electronic manipulation of DNA, proteins, and nanoparticles for potential circuit assembly

Using gold electrodes lithographically fabricated onto microscope cover slips, DNA and proteins are interrogated both optically (through fluorescence) and electronically (through conductance measurements). Dielectrophoresis is used to position the DNA and proteins at well-defined positions on a chip. Quadrupole electrode geometries are investigated with gaps ranging from 3 to 100 mum; field strengths are typically 10(6) V/m. Twenty nanometer latex beads are also manipulated. The electrical resistance of the electronically manipulated DNA and proteins is measured to be larger than 40 MOmega under the experimental conditions used. The technique of simultaneously measuring resistance while using dielectrophoresis to trap nanoscale objects should find broad applicability. (C) 2004 Elsevier B.V. All rights reserved.