Scientists have taken inspiration from one of nature’s oldest insects to create a new type of electronic nose that could one day help detect diseases, monitor pollution, improve food safety, and even strengthen national security.
Researchers at the University of California San Diego have successfully combined an insect’s natural smell receptor with an advanced semiconductor chip made from graphene.
Their study, published in Advanced Materials, demonstrates a new way to build highly sensitive chemical sensors that work much like a living nose.
The team focused on an odor receptor called MhOR5, which comes from a tiny wingless insect known as the jumping bristletail.
Like many insects, the jumping bristletail relies on an extremely sensitive sense of smell to detect chemicals in its environment. Researchers wanted to harness this remarkable natural ability and combine it with modern electronics.
To build the device, the scientists first recreated the insect’s odor receptor in the laboratory. They copied the receptor’s genetic code and inserted it into mammalian cells, which then produced the receptor protein.
After carefully purifying the protein, the researchers found that it remained stable even after being stored in a freezer for three months and could also survive repeated freezing and thawing without losing its function.
The next challenge was attaching the biological receptor to a semiconductor chip. Instead of using traditional silicon, the researchers used graphene, a one-atom-thick layer of carbon that is known for its exceptional electrical properties. Graphene is extremely sensitive to tiny changes on its surface, making it an ideal material for chemical sensing.
Using a special chemical linking process, the researchers successfully attached the insect odor receptors to graphene field-effect transistors, or gFETs. These tiny electronic devices can detect changes in electrical signals when molecules interact with the receptors.
The new sensor was then tested with 16 different organic compounds, including DEET, the active ingredient in many insect repellents, hexanol, an alcohol found in plants, and eugenol, a compound responsible for the scent of cloves. The sensor successfully detected every compound and produced different electrical responses depending on both the type of chemical and its concentration.
One of the biggest advantages of this technology is its ability to tell apart molecules that are difficult for many conventional electronic sensors to distinguish. Because the system uses a real biological smell receptor, it benefits from millions of years of natural evolution that has made insect noses remarkably sensitive and selective.
Lead researcher Professor Kiana Aran said advances in engineering, biology, semiconductor technology, and large-scale manufacturing are now making it possible to combine the remarkable sensing abilities of living organisms with modern electronics. Instead of simply studying biology, scientists can now integrate biological functions directly into semiconductor devices that can be manufactured on a large scale.
This is the first time the MhOR5 odor receptor has been directly integrated with a graphene-based transistor to create a label-free sensor for detecting small organic compounds.
The breakthrough could pave the way for a new generation of compact electronic noses that help doctors diagnose disease earlier, detect environmental pollutants, monitor food freshness, improve agricultural practices, and identify hazardous chemicals more quickly and accurately.
The study was led by researchers at the University of California San Diego and was published in the journal Advanced Materials.
