Detecting Single DNA Molecules with Optical Microcavities

About the Speaker
Frank Vollmer obtained his PhD in ‘Physics & Biology’ from the Rockefeller University NYC, USA, in 2004. He then became leader of an independent research group at the Rowland Institute at Harvard University where he was appointed Rowland Fellow from 2004 to 2009. From 2010 to 2011 he joined the Wyss Institute for Bio-Inspired Engineering at Harvard University as a Scholar-in-Residence. In 2011 he was appointed group leader (untenured associate professor) at the newly established Max Planck Institute for the Science of Light in Erlangen, Germany. Since 2011 he is also appointed as Instructor in Medicine and Associate Bioengineer at Brigham and Women’s Hospital/Harvard Medical School in Boston, USA, where he directs a satellite laboratory.Abstract
Detecting single biomolecules and their interactions is the dream of biochemists since it allows the fundamental study of biochemical reactions. Achieving biosensing capability at the single molecule level is, moreover, a particularly important goal since single molecule biosensors would not only operate at the ultimate detection limit by resolving individual molecular interactions, but they could also monitor biomolecular properties which are otherwise obscured in ensemble measurements. For example, a single molecule biosensor could resolve the fleeting interactions between a molecule and its receptor, with immediate applications in clinical diagnostics. We demonstrate single molecule biosensing with an optical microcavity biosensor platform. Using an optical microcavity and gold nanorods, we have enhanced the interaction of light with DNA to the extent that we can now track interactions between individual DNA molecules. Our approach makes it possible to use a single DNA oligonucleotide receptor and to follow its successive interactions with DNA molecules in a sample solution. Based on the duration and frequency of the measured interactions, it is then possible to detect DNA molecules, and differentiate even single nucleotide mismatches.