Tween-modified suspension array for sensitive biomolecular detection

Abstract

Suspension arrays are attracting increasing interest for detecting and quantifying proteins, nucleic acids and other biomolecules. Among various suspension arrays, sillica-based suspension arrays which benefit from low fluorescence background and material stability have been widely used. Sillica-based suspension arrays are often manufactured with the popular aldehyde-aminosilane chemistry for the attachment of a variety of biomolecules. One drawback of this immobilization strategies is the relatively high array particles lost efficiency when washed by centrifugation. Due to this shortcoming, it is low reproductivity and limited in multiplex assay. Herein we report a novel method to fabricate Tween-coated suspension sillica particles, which could achieve good-reproductivity and the low limit of detection. Tween surfactants, each containing hydrophilic ethylene glycol head groups and a hydrophobic alkyl tail, prevent silica particles from being adsorbed onto the centrifuge tube wall and make beads resuspended well. Also, Tween with low fluorescence background could reduce non-specific protein adsorption. Also Tween surfactants are economic and facile agent. In this study, we demonstrate the preparation of the protein array to substantiate the applicability of our approach. Under the optimized experiment conditions, the limit of detection of our Tween-modified particles is as low as 50 pg/mL, which is sufficiently low for the current methods. We believe that the proposed method could provide a perspective on the improvement of self-encoded silica particle arrays.