Development of a Compensated Interferometric Detector

Abstract

One family of platforms to probe molecular interactions utilizes interferometry. Interferometry has a major advantage over other techniques in that it does not require the use of labels, which could affect interactions between two molecules, in determining the extent of molecular interactions. Interferometric techniques measure refractive index (RI), a universal property of all molecules, which is affected by the binding of molecules. The refractive index of a solution has been shown to be affected by changes in conformation, charge distribution, and hydration caused by the binding of two or more molecules. Backscattering interferometry (BSI) is the only highly sensitive technique available to measure free solution binding without the use of labels.

The work described in this thesis outlines the development of a novel interferometric detector utilizing a single laser simultaneously illuminating two parallel channels in a glass microfluidic chip which has the ability to compensate for external temperature changes without the use of active temperature control. The instrument is currently able to detect RI changes on the order of 10-5 RIU, the threshold for feasibility of detecting molecular binding.