Microfluidic immunoassay platform using antibody-immobilized glass beads and its application for detection of Escherichia coli O157 : H7

Abstract

We developed a microfluidic immunoassay platform for the decision of various analytes such as bacterial pathogen by packing antibody-immobilized glass beads in spatially-isolated microchambers on a microfludic device. Primary amines of antibody were covalently conjugated to carboxyl-terminated glass beads previously treated with aminosilane followed by glutaraldehyde. Through this covalent binding, up to 905 mu g immunoglobulin G (IgG) per gram of glass beads was immobilized. For application, glass beads attaching antibody specific to Escherichia coli O157:H7, a foodborne pathogen, were packed into a microfluidic device and used for the detection of the serotype. This prototype immunoassay device can be used for the simulataneous detection of multiple analytes by sequentially packing different-sized glass beads attaching different antibody in discrete microchambers on a single microfluidic device.