[ad_1]
According to the team's research directors, microbiologist Derek Lovley and polymer scientist Todd Emrick, this work shows that it is possible to combine protein nanowires with a polymer to produce a flexible electronic composite material that maintains conductivity electrical and unique detection capabilities of protein nanowires.
Protein nanowires have many advantages over silicon nanowires and carbon nanotubes in terms of biocompatibility, stability and modification potential to detect a wide range of biomolecules and chemicals of medical or environmental interest, says lovley. However, these sensor applications require that the protein nanowires be incorporated into a flexible matrix suitable for the manufacture of portable detection devices or other types of electronic devices.
As Lovley explains, "we have been studying the biological function of protein nanowires for more than a decade, but it is only now that we can see the way forward for their use in the practical manufacture of devices. e. "
Postdoctoral research Yun-Lu Sun, currently at the University of Texas at Austin, has discovered the conditions conducive to mixing protein nanowires with a nonconductive polymer to give the electroconductive composite material. He showed that although the threads are made of protein, they are very durable and easy to process into new materials.
"An added benefit is that protein nanowires are a truly" green "and sustainable material," adds Lovley. "We can mass-produce protein nanowires with microbes grown with renewable raw materials, and the production of more traditional nanowire-based materials requires high energy inputs and some really harmful chemicals." On the other hand, he says: "Protein nanowires are thinner than silicon wires and, unlike silicon, stable in water, which is very important for biomedical applications, such as the detection of metabolites in sweat. ".
Emrick said, "These electronic protein nanowires have a surprising resemblance to polymer fibers and we are trying to find a way to combine the two more efficiently."
In their validation study, the protein nanowires formed an electrically conductive network when introduced into the polyvinyl alcohol polymer. The material can be processed under harsh conditions, such as heat, or extreme pH, such as high acidity, which could destroy a protein-based composite, but it has continued to work well.
The conductivity of the protein nanowires incorporated into the polymer has changed significantly in response to pH. "This is an important biomedical parameter for the diagnosis of some serious diseases," says Lovley. "We can also genetically engineer the structure of protein nanowires to allow, in our view, the detection of a wide range of other molecules of biomedical significance."
Electrically conductive protein nanowires are a natural product of the Geobacter microorganism discovered in the mud of the Potomac River by Lovley more than 30 years ago. Geobacter uses protein nanowires to make electrical connections with other microbes or minerals. "Material science experts such as Todd Emrick and Thomas Russell of our team deserve credit for introducing protein nanowires into the field of materials – it's not just mud anymore."
In this work supported by the UMass Amherst campus funds for exploratory research, the collaborative materials microbiology team is planning the next steps, namely increasing the production of polymer-nanowire arrays, explains Lovley.
"Material scientists need a lot more nanowires than we used to make. We made cartridges for our biological studies. They need full buckets. We are now focusing on the production of larger quantities and the adaptation of nanowires. so that they respond to other molecules ".
The researchers also filed a patent application on the idea of a conductive polymer based on protein nanowires.
Source link
