New nanostructure enhances sensitivity of biosensors

Biosensors convert a biological response into an optical or electrical signal and can be used to sense anomalies such as toxic chemicals and particles in the air, or enzymes, molecules, and antibodies in the body that could indicate diabetes, cancer, and other diseases.

According to Northwestern, an optical biosensor works by absorbing a specific bandwidth of light and shifting the spectrum when it senses minor changes in the environment. The narrower the band of absorbed light is, the more sensitive the biosensor.

‘Currently, plasmonic absorbers used in biosensors have a resonant bandwidth of 50 nanometres,’ said Koray Aydin, assistant professor of electrical engineering and computer science in the McCormick School of Engineering at Northwestern University, Illinois. ‘It is significantly challenging to design absorbers with narrower bandwidths.’

Aydin and his team have created a new nanostructure with a bandwidth of 12 nanometres, an ultra narrow band absorber that can be used for a variety of applications, including better biosensors.