MIT Researchers Develop Wireless Biosensing Technique Using Light-Detecting Antennas

MIT scientists have created a novel biosensing method that uses light to detect minute electrical signals in biological systems, eliminating the need for wired connections. This innovative approach employs tiny, wireless antennas to monitor electrical activity in cell cultures and liquid environments, offering potential advancements in understanding cellular communication and diagnosing conditions like arrhythmia and Alzheimer's.

The technique utilizes organic electro-scattering antennas (OCEANs), composed of a polymer called PEDOT:PSS. These antennas, each measuring one-hundredth the width of a human hair, detect electrical signals by scattering light differently based on nearby electrical activity. The intensity of scattered light changes proportionally to the electrical signal present in the surrounding liquid.

Benoît Desbiolles, lead author of the paper published in Science Advances,  explains, "Being able to record the electrical activity of cells with high throughput and high resolution remains a real problem. We need to try some innovative ideas and alternate approaches."

The OCEAN arrays are fabricated using precise nanofabrication techniques in MIT.nano facilities. The process involves depositing layers of conductive and insulating materials on a glass substrate, then using a focused ion beam to create nanoscale holes where the antennas "grow" from the bottom up.

In simulated experiments, the antennas demonstrated high sensitivity, detecting voltages as low as 2.5 millivolts with millisecond response times. The researchers aim to test the devices with real cell cultures and explore potential integration with nanophotonic devices.

Senior author Deblina Sarkar highlights the significance of this development: "The organic electro-scattering antennas we developed enable recording of electrical signals wirelessly with micrometer spatial resolution from thousands of recording sites simultaneously. This can create unprecedented opportunities for understanding fundamental biology and altered signaling in diseased states as well as for screening the effect of different therapeutics to enable novel treatments."