Abstract
Water is a persistent background in virtually all biosensors, yet is difficult to quantify. We apply an interferometric optical balance to measure water film accumulation from air onto several types of prepared silica surfaces. The optical balance uses in-line common-path interferometry with balanced quadratures to measure the real-time accumulation of molecular films. The accumulated water thickness is sensitive to ambient conditions, with thicknesses that vary from picometers up to nanometers, even on hydrophobic silanized surfaces. These results demonstrate that water adsorption contributes an excess signal in dry label-free protein microarray optical biosensors and presents a fundamental limit to assay sensitivity. (C) 2010 American Institute of Physics. [doi:10.1063/1.3505320]
Published in:
Applied Physics Letters 97,18 (2010)
Link to original published article:
http://dx.doi.org/10.1063/1.3505320
Date of Version
November 2010
Recommended Citation
Wang, X. F.; Zhao, M.; and Nolte, D. D., "Ambient molecular water accumulation on silica surfaces detected by a reflectance
interference optical balance" (2010). Department of Physics and Astronomy Faculty Publications. Paper 1339.
https://docs.lib.purdue.edu/physics_articles/1339