Miniature seesaw to diagnose cancer?

Mechan­ical Engi­neering grad stu­dent Samira Faegh is attempting to rev­o­lu­tionize biosensor tech­nology, which can be used in a variety of set­tings to detect any­thing from pathogens to blood glu­cose levels to mol­e­c­ular indi­ca­tors of cancer. I sat down with her last week to talk about her research, which she’s been working on for about a year.

Faegh is in the IGERT Nanomed­i­cine Pro­gram here at North­eastern, an NSF funded pro­gram that trains grad­uate stu­dents in applying nan­otech­nology to human health chal­lenges. Like many IGERT projects, Faegh’s work bridges the gap between sev­eral disciplines.

She spent the first year of her PhD reading — scouring the lit­er­a­ture for ideas in which she could merge her skills as a mechan­ical engi­neer with life sci­ence applications.

Most biosen­sors, she explained to me, use a laser to probe the mate­rial in ques­tion. They are expen­sive, bulky and com­pli­cated. Faegh wanted to design a system that would be cheaper and smaller, some­thing you could put in your pocket and use on the go.

So, how does hers work? What makes it so spe­cial? Faegh’s device uses a “micro-​​cantilever,” a tiny vibrating bar con­nected to two elec­trodes. The bar is cov­ered in a receptor bio­mol­e­cule and is then dipped into a sample solu­tion (even­tu­ally that solu­tion would be a blood sample). If the receptor is glu­cose oxi­dose (which is what Faegh’s been using so far), it will bind to any glu­cose in the sample.

Next, Faegh applies a voltage to the system through the elec­trode and the bar begins to vibrate. The rate of vibra­tion, which depends on how much binding has occurred, then sends a signal back to the elec­trode for a read out.

Faegh’s cur­rent research is to con­firm that the mech­a­nism works. Next she will try to improve the tech­nology and then even­tu­ally use it to test real blood samples.

Since this work is so inter­dis­ci­pli­nary, moving beyond just the mechan­ical engi­neering Faegh is famil­iary with, IGERT is a great way for her to be in touch with the experts she needs. “If I’m going to switch to DNA, we know a DNA person. And if we want to develop a gas sensor, then we can con­tact that person.”

Photo cour­tesy of Samira Faegh