Label-Free Method Using a Weighted-Phase Algorithm To Quantitate Nanoscale Interactions between Molecules on DNA Microarrays

Abstract

White light interference is used as a label-free method to detect nanoscale changes on surfaces. However, the signal-to-noise ratio of the white light interference method is very low, thus resulting in inaccurate results. In this paper, we report a corrected label-free method based on hyperspectral interferometry to overcome the shortcoming of the white light interference method. A platform based on hyperspectral interferometry was established, and a DNA hybridization microarray was constructed to quantitate thickness variation of molecules on a solid surface. We used fluorescence resonance energy transfer (FRET) to validate the results of our method. Compared to conventional fluorescence-labeled method like FRET, our method has advantages because it does not require a fluorescent label and has a detection limit of 1.78 nm, a high accuracy, and wide detection range (5-64 bp).