FIELDS COLLIDE AS RESEARCHER DEVELOPS HYBRID DISCIPLINE TO BUILD BIOSENSOR
Hanbin Mao received his Ph.D. from Texas A&M University in the field of analytical chemistry. He did his post-doc at The University of California at Berkeley in the field of biophysics.
When he came to Kent State University in 2005, he had hopes of combining the two disciplines to create an entirely new niche field for himself.
“At first, in my lab, I had no idea how to combine them, so I just worked separately in the two different fields,” he said.
Now a grant from the National Science Foundation has made his dream a reality. Mao just received a two-year $200,000 grant from the NSF that puts his two research foci in use in a new field he’s called mechano-analytical chemistry. The NSF grant allows Mao and his lab staff to establish novel methods in single-molecule mechano-chemical sensing (SMMS), a transformative sensing strategy pioneered by Mao since 2014.
“This is the first major federal funding for this part of the research,” he said.
The work, born form the bioanalytical chemistry side of his research, has been funded privately by the Camille and Henry Dreyfus Foundation since Mao began at KSU in 2005.
Mao specializes in single-molecule biophysics, dealing with individual molecules of DNA, RNA and proteins. Most specifically, his lab studies the G-quadruplex — a four-strand DNA complex necessary for the formation of cancer cells.
They also worked on and off in the bioanalytical chemistry field, using bio-sensing to identify biological markers that indicate the presence of cancer or other diseases.
The fields collided when Mao’s team began using “laser tweezers” — exactly what they sound like — to hold single nanometer-to-micrometer-sized beads in place a short distance from each other, and tethered a single DNA molecular strand in between them.
The strand acts as a probe or a sensing template.
“The next step of this is that the tension of that strand can be monitored in real time,” Mao said. “If another molecule, like a bio-marker, enters that strand, it changes the tension.”
The mechano-chemistry aspect of it comes into play when coupling occurs. The DNA, RNA or protein strands, have a tendency to fold over on themselves, creating a tertiary — or 3D — structure, Mao said. By using the laser tweezers to pull on the strand at both ends, it unties the fold, like a knot in a piece of string.
“So what you have is mechanical energy countering or undoing the effects of chemical energy,” he said. “It can go in reverse too, and you may have a kind of tug-of-war depending on which energy is greater.”
The new sensory biotechnology has profound implications for early detection and diagnosis of cancer. However, Mao said, its applications can be used in detecting antibodies or the presence of bacterial pathogens, and it can even extend to identifying toxic materials like mercury or lead in water. In a recent example that resulted in a patent application, Shankar Mandal, a graduate student from the Mao research lab, has used SMMS to evaluate mercury concentration in Lake Erie.
“Our next goal, beyond early detection, is to be able to screen drugs for diseases, with sensory targeting,” he said.
For more information on Kent State Research, contact Dan Pompili, at 330-672-0731 or firstname.lastname@example.org