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Journal of Sensors
Volume 2011, Article ID 507047, 10 pages
Research Article

Improvement of Accuracy in Flow Immunosensor System by Introduction of Poly-2-[3-(methacryloylamino)propylammonio]ethyl 3-aminopropyl Phosphate

1Department of Chemical Science and Technology, Graduate School of Advanced Technology and Science, The University of Tokushima, 2-1 Minamijosanjima, Tokushima-shi, Tokushima 770-8506, Japan
2Health Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), 2217-14 Hayashicho, Takamatsu, Kagawa 761-0395, Japan

Received 9 November 2010; Revised 23 March 2011; Accepted 15 June 2011

Academic Editor: Jiri Homola

Copyright © 2011 Yusuke Fuchiwaki et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


In order to improve the accuracy of immunosensor systems, poly-2-[3-(methacryloylamino)propylammonio]ethyl 3-aminopropyl phosphate (poly-3MAm3AP), which includes both phosphorylcholine and amino groups, was synthesized and applied to the preparation of antibody-immobilized beads. Acting as an antibody-immobilizing material, poly-3MAm3AP is expected to significantly lower nonspecific adsorption due to the presence of the phosphorylcholine group and recognize large numbers of analytes due to the increase in antibody-immobilizing sites. The elimination of nonspecific adsorption was compared between the formation of a blocking layer on antibody-immobilized beads and the introduction of a material to combine antibody with beads. Determination with specific and nonspecific antibodies was then investigated for the estimation of signal-to-noise ratio. Signal intensities with superior signal-to-noise ratios were obtained when poly-3MAm3AP was introduced. This may be due to the increase in antibody-immobilizing sites and the extended space for antigen-antibody interaction resulting from the electrostatic repulsion of poly-3MAm3AP. Thus, the application of poly-3MAm3AP coatings to immunoassay beads was able to improve the accuracy of flow immunosensor systems.