By Scott Gordon
When Arjun Seshadri decided to study engineering, he wasn’t necessarily thinking about medical applications. That changed when he discovered the UW-Madison Lab for Molecular Scale Engineering.
Before his freshman year was over, he became a research assistant in the lab under former Electrical and Computer Engineering Professor Robert Blick and his graduate students.
Currently a senior in electrical and computer engineering, Seshadri found his passion in the development of a device that uses radio waves to measure the activity of proteins in cell membranes. The technology, described in a 2013 paper in Soft Nanoscience Letters, offers an improvement on current methods with application areas including DNA sequencing and understanding ion channels, proteins that play an essential role in cell regulation and communication. The device could also potentially be used to detect cancerous cells in blood. “It was only when I ran into this stuff that I realized I wanted to do work that could make an impact, that others would pay attention to,” Seshadri says. “This project was a great way for electrical engineering concepts to be applied in a sense that was very directly relevant to real people.”
Current techniques for ion channel research use direct current to measure, say, how a specific protein reacts to a change in voltage or the introduction of a given chemical. The Blick group’s device instead uses radio frequencies, which could enable a more detailed and more real-time analysis. “The advantage to our setup is that we can detect things very quickly, because we’re working on radio frequencies around 250 MHz,” Seshadri says.
Abhishek Bhat, a grad student and lead author of the 2013 paper, says the group aims to analyze ion channel activity at a nanosecond time scale. “In simple terms, we should be able to reliably sequence over 100 million DNA bases every second,” Bhat says. “The current record stands at just about 1 million.”
Realizing those ambitious time-domain goals is Seshadri’s focus as the group prepares to submit another paper. The group’s published research so far shows experimental successes in the frequency domain. Seshadri is also beginning to work with a company in San Diego that might adapt the technology for DNA sequencing.
The device could eventually impact medical research on a much broader scale, though, especially when it comes to studying ion channels. “Ion channels are the basic communication and regulation means for cells,” Bhat says. “The heart beats due to these channels firing; all neurons communicate via these channels; touch, hearing and all senses are governed at a cellular level by these channels. There are quite a few illnesses that occur due to the channels not functioning correctly. This makes the channels extremely important for study, especially for pharmaceutical applications.”
Seshadri says that doing graduate-level research in his freshman year took dedication and a welcoming group of mentors. “Being a freshman, I barely knew circuits, so a lot of the work I had to do was just taking a textbook, taking three days off and going to the basement of Engineering Hall and just reading,” he says. “The group was really accepting of the fact that I initially didn’t know a lot, and they pointed me in the right direction to learn and catch up. I got to do a lot of learning in a very short period of time.”