‘Green’ Electronic Materials Produced with Synthetic Biology

'Green' Electronic Materials Produced with Synthetic Biology
Synthetic biowire are making an electrical connection between two electrodes. Researchers led by microbiologist Derek Lovley at UMass Amherst say the wires, which rival the thinnest wires known to man, are produced from renewable, inexpensive feedstocks and avoid the harsh chemical processes typically used to produce nanoelectronic materials. Credit: UMass Amherst

Scientists from the University of Massachusetts have developed a new strain of bacteria. These bacteria draw out extremely thin and highly conductive wires. These wires are made up of harmless, natural amino acids. The wires developed from renewable, cheap feedstocks and avoid the harsh chemical processes typically used to produce Nano electronic materials. With the ability to produce mass, this tenable technology comes with many applications in electronics, transistors, and capacitors. It can be used in biocompatible sensors, computing devices, and as solar panel’s components.

Derek Lovley, the research leader, said, “New sources of electronic materials are required to fulfil the growing requirement for making smaller, more powerful electronic devices in a continuous way.”

This advance starts before a decade when Lovley and team that Geobacter. Geobacter is a common soil microorganism, which could create microbial nanowires. Microbial nanowires are electrically conductive protein filaments that help the microbe to become on the iron minerals abundant in soil. After that, they learned about how these microbial nanowires work. And we came to know that a class of amino acids was important for the conductivity. Thus, they reconstruct amino acids for generating a synthetic nanowire that is more conductive.

The trick they discovered to accomplish this was to introduce tryptophan. Tryptophan is a common aromatic amino acid which is not present in natural nanowires. It causes deadness after eating thanksgiving turkey. It is also highly effective at the nanoscale in transporting electrons.

At last, they designed a synthetic nanowire in which tryptophan is involved whereas nature had used a phenylalanine and put in another tryptophan for one of the tyrosine.

Lovley said, “We hoped to get lucky and that Geobacter might still form nanowires from this synthetic peptide and maybe double the nanowire conductivity.”

They inherently developed a strain of Geobacter and manufactured large quantities of the synthetic nanowires. These nanowires are 2000 times more conductive as compared to the organic product. The synthetic nanowires with a diameter only half of the organic product were inserted into it. Lovley called it as biowire.

“The results are mind-blowing. The conductivity of biowire exceeds that of many types of chemically produced organic nanowires with similar diameters. The extremely thin diameter of 1.5 nanometers means that thousands of the wires can easily be packed into a very small space,” he said.

Scientists did not need any harmful chemicals that are needed for synthesis of other nanowires for making biowires. Also, biowire does not compose with any harmful components. Generating Geobacter is a very green process. It can be created by cheap renewable feedstocks. Similarly, the biowire consists of protein and extremely durable. Lovley’s lab had to work for months to establish a method to break it down.

“It’s quite an unusual protein. This may be just the beginning. We hope that our initial success will attract more funding to accelerate the discovery process. Similarly, we also hope that we can modify biowire in other ways to expand its potential applications,” said Lovley.

Researchers in his lab recently produced more than 20 other Geobacter strains. Each Geobacter generates a definite Biowire variant with new amino acid combinations.

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