Methodology

Reusable, polyethylene glycol-structured microfluidic channel for particle immunoassays

Jin-Hee Han and Jeong-Yeol Yoon^*

• * Corresponding author: Jeong-Yeol Yoon jyyoon@email.arizona.edu

Author Affiliations

Department of Agricultural and Biosystems Engineering, The University of Arizona, Tucson, Arizona 85721-0038, USA

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Journal of Biological Engineering 2009, 3:6 doi:10.1186/1754-1611-3-6

Published: 28 April 2009

Abstract

A microfluidic channel made entirely out of polyethylene glycol (PEG), not PEG coating to silicon or polydimethylsiloxane (PDMS) surface, was fabricated and tested for its reusability in particle immunoassays and passive protein fouling, at relatively high target concentrations (1 mg ml^-1). The PEG devices were reusable up to ten times while the oxygen-plasma-treated polydimethyl siloxane (PDMS) device could be reused up to four times and plain PDMS were not reusable. Liquid was delivered spontaneously via capillary action and complicated bonding procedure was not necessary. The contact angle analysis revealed that the water contact angle on microchannel surface should be lower than ~60°, which are comparable to those on dried protein films, to be reusable for particle immunoassays and passive protein fouling.