Researchers have invented a new nano optical biosensor that can be used to detect cancer

2024-01-02

Biosensors are important diagnostic equipment that must be fast, inexpensive, and easy to use. If the biosensor has a compact appearance and can be operated autonomously, it can be used by both doctors and patients themselves, making it highly valuable. Most optical biosensors require a wide range of light colors as the basis (like a rainbow) to operate reliably, and the demand for a wide range of light colors makes sensors bulky, expensive, and more complex.

Most biosensors today require a spectrometer to extract data from each color of light, limiting their use. EPFL scientists have proposed a new concept that allows a single color of light to operate as a simple imaging detector. Although only using a single color of light, the system provides extremely accurate biometric information, just like the entire rainbow colored light illuminating the sensor.

The new biosensors utilize two specific functionalities, including nanophotonics and data science technologies. The chip itself is constructed from a nanostructure made of silicon. The surface of nanostructured silicon has a characteristic of around 100 nanometers, which can more effectively capture light at the interface of biological samples/chips. This makes the biosensor highly sensitive to the presence of biomarkers, resulting in significant changes in the characteristics of incident light.

This feature is the variation in the amount of light collected, known as light intensity. Usually, cameras continuously receive light passing through the biochip and obtain intensity information of millions of image pixels from the biochip. The biomarkers and intensity change images attached to nanostructures on biochips are compiled at very high resolution by inducing intensity changes for each pixel.

Researchers combine data science techniques with pre recorded performance maps to process light intensity information from a large number of pixels. The system considers the efficiency of each pixel and collectively adjusts its contribution to the final reading. Researchers liken this process to carefully weighing their knowledge in the field and drawing a reliable conclusion after receiving opinions from a group of experts.

The scientists of this project created a demonstration using a new biosensor for cancer diagnosis, detecting tumor exons, which are biomarkers for early cancer. The team determined that image-based biosensors can monitor breast cancer exons in real time within a wide range of detection, making them clinically meaningful for both healthy and sick people.

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