A microscopic bit of matter in solution is in continuous motion. Pummelled at random by the solvent, it engages in a randomly directed walk that will eventually take it far away from where it was first observed. At the nanoscale, even gravity is too weak to influence the trajectory of the object, however, placing surfaces in the vicinity puts new forces into play.
By appropriately tailoring the geometry of the walls, Professor Krishnan’s research group is able to harness these intrinsic object–wall forces and manoeuvre their entity of interest into a desired spatial location and orientation in a fluid. Once there, the object levitates stably for long periods.
The group are pioneering the use of the "electrostatic fluidic trap" in order to realise new experiments in the spatial control, manipulation, and measurement of nanoscale matter in solution. Their primary focus is on biological molecules such as proteins and DNA. Using this new approach to trapping molecules they have developed a way to measure the electrical charge of a single biomolecule in solution with high precision.
Not only does this new measurement technique open up hitherto unforeseen avenues in fundamental science, but the technological implications for society are significant. The electrostatic fluidic trap provides a new technological platform for highly sensitive and precise measurements of small changes in biomolecular properties that could be central to the diagnosis and detection of disease states and may therefore make a significant contribution to diagnostic and biomedical detection approaches of the future.
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Professor Madhavi Krishnan is currently Associate Professor of Physical Chemistry at the University of Oxford. She completed her undergraduate work at Anna University, Madras, India followed by a PhD at the University of Michigan at Ann Arbor. Supported by Alexander von Humboldt and Marie Curie Fellowships she carried out postdoctoral work in single molecule biophysics and nano-optics at Technical University Dresden and ETH Zurich respectively.
In 2012, following a brief stint as a Visiting Scholar at Harvard School of Engineering and Applied Sciences she was appointed Assistant Professor in Physical Chemistry at the University of Zurich and received a Professorship of the Swiss National Science Foundation.
She was awarded the 2016 Nernst- Haber-Bodenstein prize of the German Bunsen Society for Physical Chemistry for her research which examines molecular electrostatics in the fluid phase, including both experiment and theory.
At Oxford since 2018, Professor Krishnan leads a multi-disciplinary research team at the Physical and Theoretical Chemistry Laboratory supported by an ERC Consolidator Grant. At various stages her research has received broad press coverage including in leading national dailies like NRC Handelsblad (Netherlands) and Neue Zuercher Zeitung (Switzerland).