Putting on the heat
Viruses can be useful in many applications, including vaccines, gene therapy and agriculture. Now, Berkeley researchers have found — for the first time — that viruses can generate electricity when exposed to heat, a phenomenon known as pyroelectricity. This finding may pave the way for next-generation biosensors and diagnostic tools.
“We discovered that when we apply heat to virus particles, they undergo structural changes that lead to changes in spontaneous polarization and the generation of electric potential,” said bioengineering professor Seung-Wuk Lee.
Lee and his team first demonstrated the bioelectric potential of the engineered M13 virus more than 10 years ago. In this latest work, the researchers genetically engineered a portion of the M13 phage’s protein coating, then observed and measured the virus’ electric response to heat. According to Lee, their findings showed that heat denatures, or melts, the protein coating on the engineered phage, causing a difference in electrical potential.
Next, the researchers investigated the M13 phage’s pyroelectric responses to other molecules. Peptides genetically tuned to be responsive to specific nonvolatile and volatile organic compounds were attached to the protein coating of the engineered pyroelectric phages. When these phages were exposed to the different solvents, they generated different pyroelectric responses depending on chemical species and their concentrations.
“Our findings showed that, depending on the chemical receptor, we could easily detect a harmless or a toxic chemical, like xylene,” said Lee.
The researchers believe this work could eventually lead to handheld devices that use pyroelectricity to sense other viruses and detect new strains, and it could also shed light on how biomaterials — cells, tissues and proteins — generate electricity at a molecular level.
Learn more: Researchers demonstrate heat-induced pyroelectricity in viruses; Virus-based pyroelectricity (Advanced Materials)