Electronic Nose Built With Ammonia-Sensitive Nanowires Can Sniff Chemicals to Monitor Health Complications

A human nose has hundreds of receptors sensitive to one specific molecule. Due to its efficiency, researchers thought of creating an electric nose that could sniff out disease to make health monitoring much easier and faster.

Electronic Nose With Nanowire To Sniff Diseases

Researchers from the University of Massachusetts Amherst announced the invention of a nanowire that is 10,000 times thinner than human hair, cheaply grown by common bacteria, and can smell chemicals given off by people with asthma and kidney disease.

The nanowires can be layered onto tiny, wearable sensors for healthcare providers to monitor health complications. Since the wires are grown from bacteria, they are organic, biodegradable, and even greener than inorganic wire, Science Daily reported.

Senior authors Derek Lovley, a distinguished Professor of Microbiology at UMass Amherst, and Jun Yao, a professor of electrical and computer engineering in the College of Engineering at UMass Amherst, ended up with the breakthrough by studying human noses. Yao said they considered leveraging biological design rather than synthetic material.

They started with the bacterium known as Geobacter sulfurreducens, which has been used to create biofilm capable of producing long-term continuous electricity from sweat. It has the natural ability to grow tiny, electrically conductive nanowires.

Lovely said they took the nanowire gene called pilin out of G. sulfurreducens and spliced it into the DNA of Escherichia coli, one of the most common bacteria in the world.

When they removed the pilin gene, they modified it to include a specific peptide known as DLESFL, which is extremely sensitive to ammonia - a chemical present in those with kidney disease. They spliced the modified pilin gene into E.coli's DNA and tweaked bacterium sprouted tiny nanowires bristling with the ammonia-sensitive nanowires and built them into a sensor.

Yassir Lekbach, the paper's co-lead author and a postdoctoral researcher in microbiology at UMass Amherst, said the genetically modified nanowires are more sensitive to ammonia, and the microbe-produced nanowires work better as sensors than the previous ones designed with traditional silicon or metal nanowires.

Nanowires Sensors to Sense Diseases

The genetically modified nanowires only sensed ammonia and kidney disease during the research. However, the study is very promising as it can be expanded to do more.

Toshiyuki Ueki, the paper's other co-lead author and research professor in microbiology at UMass Amherst, said they could design unique peptides, each of which specifically binds a molecule of interest. The more tracer molecules specific to a particular disease are identified, the more sensors they can make and incorporate hundreds of different chemical-sniffing nanowires to monitor more health conditions in the future.

Since Lovely and Yao's nanowires are grown from common bacteria, they are sustainable. Yao added that they are excited about the research because it uses life's genetic design to build a stable, versatile, cost-effective platform. He said through the study; they are taking electrical engineering in a new direction.

Additionally, their nanowires are safer because traditional ones made from silicon or carbon fiber are highly toxic, and carbon nanotubes are carcinogens and end up as non-biodegradable e-waste.

The National Science Foundation supported the research and nurtured by the Institute for Applied Life Sciences (IALS) at UMass Amherst, which combines deep and interdisciplinary expertise from 29 departments to translate fundamental research into innovations for human health and well-being.

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