Superparamagnetic bead interactions with functionalized surfaces characterized by an immunomicroarray

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Peter Durand Skottrup, Mikkel Fougt Hansen, Jacob Lange Moresco, Maria Deryabina, Winnie Edith Svendsen, Mogens Havsteen Jakobsen, Martin Dufva

Magneto-resistive sensors capable of detecting superparamagnetic micro-/nano-sized beads are promising alternatives to standard diagnostic assays based on absorbance or fluorescence and streptavidin-functionalized beads are widely used as an integral part of these sensors. Here we have developed an immunomicroarray for systematic studies of the binding properties of 10 different micro-/nano-sized streptavidin-functionalized beads to a biotin substrate immobilized on SiO2 with or without surface modification SiO2 surface cleaning, immobilized substrate concentration and surface blocking conditions were optimized Polyethylene glycol-based surfaces with different end groups on the anchor molecule, 2,4,6-trichloro-1,3,5-triazine (TsT), were synthesized and compared with the standard (3-aminopropyl)triethoxysilane (APTS)/glutaraldehyde chemistry APTS/glutaraldehyde, directly linked TsT and bare H2O2-activated SiO2 performed better than polyethylene glycol-modified surfaces Two beads, Masterbeads and M-280 beads, were found to give superior results compared with other bead types. Antibody/ antigen interactions, Illustrated by C-reactive protein, were best performed with Masterbeads The results provide important information concerning the surface binding properties of streptavidin-functionalized beads and the immunomicroarray can be used when optimizing the performance of bead-based biosensors.
Original languageEnglish
JournalActa Biomaterialia
Volume6
Issue number10
Pages (from-to)3936-3946
Number of pages11
ISSN1742-7061
Publication statusPublished - 2010

ID: 33238365