Work

Ambient molecular water accumulation on silica surfaces detected by a reflectance interference optical balance

Year: 2010

Type: article

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.

Source: Applied Physics Letters

DOI: 10.1063/1.3505320

Authors: Xuefeng Wang, Ming Zhao, David D. Nolte

Institution: Purdue University West Lafayette

Language: English

Topic: Advanced Biosensing Techniques and Applications

Subfield: Molecular Biology

Field: Biochemistry, Genetics and Molecular Biology

Domain: Life Sciences

Open Access status: bronze

Funders: Purdue University, Purdue Research Foundation, National Institutes of Health, National Cancer Institute

Award: Multiplexed Assays on the BioCD for Acute Lymphocytic Leukemia