Top-down meets bottom-up: Dip-pen nanolithography and DNA-directed assembly of nanoscale electrical circuits

The hybridization of DNA that can be used to direct the assembly of single DNA-functionalized nanoparticles into single-electrode junctions and the use of DPN in interfacing DNA-diorected nanoparticle assembly to produce primitive tunnel junction circuits was demonstrated. After nanoparticle hybridization, the chips were wire-bonded and inserted into a continuous flow He cryostat for electrical characterization at different temperatures. DPN was used to produce devices with different DNA sequences on neighboring junctions on the same chip. These junctions provide the opportunity to measure electrical transport through well-defined biochemical tunnel junctions and the opportunity to develop simple biosensors based on basic on/off-type recognition events. Several existing self-assembly schemes require a means of interfacing chemical and biochemical functionality with conventional micro- and macro-structures.