Biological detection by means of mass reduction in a suspended microchannel resonator

Abstract

Label-free detection is the detection of biomolecules and their interactions, without the use of a molecule external to the interaction, used as a reporter to indicate presence and/or location. The suspended microchannel resonator offers the opportunity to perform such label-free measurements. The goal of this work is to open new avenues of possible applications for the suspended channel. I introduce the concept of detecting mass subtraction as a new approach, rather than the conventional detection of mass addition. In a model implementation scenario of this approach, a mass-intensifying tag bound to a small ligand molecule will be equilibrated with surface-immobilized receptors, and later displaced by an identical, but label-free, ligand molecule. This approach offers opportunities to extend the sensitivity range of the device, as well as introduces new functionality for it. It enables researchers to follow, label-free, real-time enzymatic reactions, relative affinities of different ligands to a receptor, and presence of small molecules in a solution.