Harnessing Butterfly Vision to Enhance Cancer Detection

A sensor emulating the ultraviolet (UV) vision of butterflies, created by scientists at the University of Illinois, exhibits the ability to detect UV light and accurately differentiate cancerous cells from normal cells with a 99% success rate. This cutting-edge sensor integrates perovskite nanocrystals with established silicon technology, paving the way for use in cancer surgeries and biological studies. This endeavor has garnered substantial support from U.S. financial sources. The sensor is visually represented alongside a butterfly in an artistic rendition by The Grainger College of Engineering at the University of Illinois Urbana-Champaign.

The animal kingdom hosts a variety of creatures with sensory capabilities far beyond human faculties. For instance, turtles can sense the Earth’s magnetic field, while mantis shrimp have the capacity to see polarized light. Elephants have the ability to hear subsonic frequencies, undetectable to humans. Similarly, butterflies have a vision that encompasses a wider spectrum, including the ability to see UV light.

Drawing inspiration from the Papilio xuthus butterfly’s superior vision, researchers have engineered an imaging sensor that can detect UV light beyond the human visible spectrum. The sensor’s architecture, which features a layered combination of photodiodes and perovskite nanocrystals (PNCs), enables it to image various UV wavelengths. It can also distinguish between cancer cells and normal cells with high accuracy by interpreting the unique spectral signatures of biomedical markers like amino acids.

This breakthrough research is spearheaded by Viktor Gruev and Shuming Nie, professors of electrical and computer engineering and bioengineering respectively, at the University of Illinois Urbana-Champaign. Their findings have been published in the journal Science Advances.

Subtle Differences

“Butterflies can see the subtle differences in the UV spectrum much like we perceive different shades of colors,” explains Gruev. He expresses fascination with how butterflies achieve this despite UV light’s tendency to be absorbed rather than captured. By incorporating novel perovskite nanocrystals with silicon-based imaging technology, the team’s camera is able to detect multiple UV regions effectively.

UV light, a form of electromagnetic radiation with shorter wavelengths than visible light but longer than x-rays, is categorized into UVA, UVB, and UVC bands. Humans are generally unaware of UV radiation except for its presence in sunlight and its potential health hazards.

Butterflies, in contrast, are sensitive to these minute variations in the UV spectrum. Gruev notes the remarkable nature of their ability to perceive these differences so well.

Mimicking Nature

Human vision is trichromatic, relying on three types of photoreceptors sensitive to red, green, and blue. Butterflies’ compound eyes, on the other hand, have six or more types of photoreceptors including those sensitive to violet, ultraviolet, and broadband light. Their eyes also contain fluorescent pigments that transform UV into visible light, which their receptors can then detect, allowing them to see an expanded range of colors.

The University of Illinois team replicated the butterfly’s UV sensing ability by placing a layer of PNCs atop a structured array of silicon photodiodes. PNCs, semiconductor nanocrystals with unique properties, are especially adept at detecting UV wavelengths that traditional silicon detectors cannot. When layered in the new sensor, these PNCs absorb UV photons and re-emit them in the visible spectrum for the silicon photodiodes to detect. This conversion and detection process enables the mapping of UV signatures.

Applications in Health and Science

Different concentrations of biomedical markers found in cancerous tissues, like amino acids, proteins, and enzymes, become visible when excited by UV light, a phenomenon known as autofluorescence. This difference in spectral signatures between cancerous and healthy cells allows for their distinction. The team’s imaging device has proven its capability to discern between cancerous and healthy cells with a high degree of certainty.

Gruev and Nie, along with their research collaborators, anticipate the sensor’s application in surgical settings to assist in determining the extent of tissue removal necessary to achieve clean margins. This sensor promises to aid surgeons in differentiating between cancerous and non-cancerous tissues during tumor excisions.

Expanding beyond healthcare, Nie anticipates this imaging technology will open new avenues for biological exploration, including studying the behaviors of other UV-sensitive species and aquatic environments where UV light penetrates and influences the underwater ecosystem.

This research has received funding from the U.S. Air Force Office of Scientific Research, the Office of Naval Research, the National Science Foundation, the National Institute of Health, and the University of Illinois Institutional Funds.

Frequently Asked Questions (FAQs) about UV imaging sensor technology

More about UV imaging sensor technology

• Bioinspired UV Imaging Sensor Technology
• Understanding Butterfly Vision
• Applications of Perovskite Nanocrystals
• The Role of Autofluorescence in Cancer Detection
• The Grainger College of Engineering at UIUC
• Science Advances Journal
• National Science Foundation Research Support
• National Institute of Health Research Funding