DNA Assembled Nano-Transistors

Bob Vila's Hammer writes "In an article at New Scientist, researchers at the Technion-Israel Institute of Technology have harnessed DNA to mold a nano-transister constructed of graphite nanotubes coated in silver and gold. The carbon nanotube assembly when completed is a fully working transistor when voltage is applied. The process is ingenious, using proteins from E. Coli bacterium to bind carbon nanotubes to certain sites on strands of DNA. Then graphite nanotubes coated with antibodies connect to the proteins. Finally, silver ions are added to the solution which chemically bond with the DNA site where the protein is attached. Further refinement of the technique is required before full scale production would be efficient, but this could allow the creation of elaborate self-assembling DNA sculptures and circuitry."

Comments

Nothing New Here, Move Along

[thelizman]

This process was first performed at MIT by Angela Belcher. She was using engineered viruses that coated themselves with semiconductor materiel to produce nanoscale FET trasnsitors a billionth of a meter in size. You can read more in the November issue of IEEE Spectrum.

Re:Nothing New Here, Move Along

[popeyethesailor]

I thought IEEE spectrum mentioned Dr.Belcher was close to building it. It didnt say there was actually a device built. The Newscientist article says they have actually realized this goal.

I presume the article you are referring to is this

Nothing New - Faraday

[Anonymous Coward]

Michael Faraday did this years ago (use google). The only thing these guys brought to the table is the capacitance reactivity factor is about 43% of the original magnitude of Faraday's experiments.

As a scientist in this field, I can say that this technology is still pretty wild and untested. You won't see anything come out of this for at least a decade, and even then, it probably won't get any further than Faraday's original result (he was eaten by a bio-thermo-electrolitic legume, aka a synthetic bean).

Adapt the proteosynthesis process

[G4from128k]

A better process would be to adapt the proteosynthesis process for creating micro-polypeptide clusters that are circuit elements with highly specific binding sites for self assembly. A DNA sequence would encode an mRNA sequence that is passed to a ribsome-like micro-factory. An alphabet of tRNA units would carry heavily modified amino-acids and provide both the electrical and structural of properties of the polypeptide. Different polypetides might make transistors, autonomous clock circuits, chemical-to-electrical battery subunits, wires, tees, etc.

Part of the DNA sequence would encode binding sites that are highly specific. Each electrical component would have a unique code on each terminal that only binds with the component that it connects to in the circuit. By labelling all the terminii of the components with these specific binging patterns, you the potential for self-assembly. To make a complex circuit, you make separate batches of each component, then mix the batches together and they self-assemble into the circuits. Thus, a soup of appropriately labeled transistors and wires would self-assemble into a soup of full-adder circuits.

The use of larger-scale binding sites would enable hierarchical self-assembly of self-assembled micro-components (e.g., a soup of 1-bit full-adder circuits might self-assemble into a 8-bit full-adders, or 8-bit full-adders might bind to a gated accumulator registers, etc.)

I doubt this technology would let you create a 64-bit processor - the binding-site combinatorics get too ugly. But it might let you create RAM, RFID circuits, or small CPUs (e.g., the Intel 8080 only needs 6000 transistors)