Researcher Wei Zhou is channelling his interest in human physiology and biochemistry to develop nano-antennas — incredibly tiny electrodes that go inside cells.
“We want to get information from within the cells,” Zhou, associate professor in the Bradley Department of Electrical and Computer Engineering, explains “whether metabolite molecules, protein biomarkers, or even genetic information. But getting that information from within the cell without killing it is actually a very difficult challenge.”
The conventional method for getting cellular information is called endpoint analysis. Here cells are extracted for discovery. Once the cells are extracted in a biopsy, the information they provide is finite — the cells are no longer connected to a living biological system.
The new alternative are small, bio-interfacing tools: nano-optoelectrodes. As hybrid electrical-optical devices and sensors, nano-optoelectrodes are capable of reading both biochemical fingerprints and electrical activities of a cell’s molecules in a continuous, real-time stream.
The multifunctional nature of the optoelectrodes sets it apart from other bio-interfacing tools because it fuses a nano-antenna — a microscopic version of the large-scale antennas we interact with every day, such as radio towers — and nano-electrodes, which are devices that deliver or take out electricity, like welding tools or batteries.
The optoelectrode design even mimics its full-sized counterparts, built into shape called a nanopillar.
“Due to the structure of the nano-optoelectrodes, it can trick the cell into engulfing it,” Zhou observes. “We use a short-pulsed laser to induce vapor nano-bubble generation, so the device can penetrate through the cell membrane and send out electrical signals.”
That nano-bubble generation is called optoporation, a pinpoint zone of heat that temporarily vaporizes a tiny hole in the cell membrane. This is a precise and minimally invasive type of nano-surgery.
Unlike in endpoint analysis, where cells are removed from the body and permanently destroyed in the process of extracting data, the optoelectrodes go inside the cells and stay there.
Once inside the cell, the nano-optoelectrodes employ artificial intelligence capable of machine learning to process and send out the intracellular data.
The future of the research is set to create and deploy large-scale nano-optoelectrode arrays in wearable or implantable devices that go beyond today’s fitness trackers, smartwatches, and blood pressure monitors. This includes use in forms of targeted therapy, as cancer treatments specifically designed to target the proteins that control how cancer cells grow, divide, and spread.