UT Host: Dr. Thanh Do

Speaker: Dr. Hanbin Mao

Professor of Chemistry and Biochemistry

Kent State University

Title: “Single-Molecule Mechanochemical Sensing”

Typical biosensors employ two components, molecular recognition and signal amplification, which are spatiotemporally decoupled. As the amplification requires time to finish, it is challenging for biosensors to detect analyte in real time, which is highly desirable when a ligand is transiently associated with the recognition component. Another problem for decoupled sensing components lies in the fact that extra steps are required to prevent the cross-talks between the two components.  These additional steps may deteriorate the signal-to-noise of the sensing.  In this talk, I will discuss a new sensing strategy that exploits mechanochemical coupling inside biomacromolecular templates, DNA in particular. Mechanochemical coupling describes the conversion between the chemical binding energy and the mechanical energy associated with the conformation change of a sensing receptor upon ligand binding. Using force-based single-molecule techniques such as optical tweezers, our group has been able to follow the change in the tension of individual DNA templates upon target recognition. The mechanochemical coupling occurs instantaneously, enabling real time detection of analytes.  Since the template we use is single-molecular in nature, the ultimate single-molecule sensitivity can be achieved in this sensing. Combined with microfluidic platforms, this sensing strategy has allowed us to detect picomolar concentrations of specific targets in biological samples.

Professor Hanbin Mao got his PhD training in Analytical Chemistry at Texas A&M University in 2003. After two years of postdoctoral research at UC Berkeley specializing in single-molecule force spectroscopy, Dr Mao joined the Department of Chemistry and Biochemistry at Kent State University in 2005. His research is focused on biosensing and single molecular biophysics. His research lab in Kent State has developed a new interdisciplinary field, mechano-analytical chemistry, in which mechanical properties of molecules have been exploited for (bio)chemical analyses and mechanochemistry studies.