Self-Assembly of Soft Cellulose Nanospheres into Colloidal Gel Layers with Enhanced Protein Adsorption Capability for Next-Generation Immunoassays

Soft cationic core/shell cellulose nanospheres can deform and interpenetrate allowing their self-assembly into densely packed colloidal nanogel layers. Taking advantage of their water-swelling capacity and molecular accessibility, the nanogels are proposed as a new and promising type of coating material to immobilize bioactive molecules on thin films and paper. The specific and nonspecific interactions between the cellulosic nanogel and human immunoglobulin G as well as bovine serum albumin (BSA) are investigated. Confocal microscopy, electroacoustic microgravimetry, and surface plasmon resonance are used to access information about the adsorption behavior and viscoelastic properties of self-assembled nanogels. A significant BSA adsorption capacity on nanogel layers (17 mg m-2 ) is measured, 300% higher compared to typical polymer coatings. This high protein affinity further confirms the promise of the introduced colloidal gel layer, in increasing sensitivity and advancing a new generation of substrates for a variety of applications, including immunoassays, as demonstrated in this work.

Publication year: 2020
Authors: Solin K. 1, Beaumont M. 1,2, Rosenfeldt S. 3, Orelma H. 4, Borghei M. 1, Bacher M. 2, Opietnik M. 5, Rojas O. J. 1,6

1 – Department of Bioproducts and Biosystems, School of Chemical Engineering, Aalto University, Vuorimiehentie 1, Espoo, FI-00076, Finland
2 – Department of Chemistry, Institute of Chemistry for Renewable Resources, University of Natural Resources and Life Sciences Vienna (BOKU), Konrad-Lorenz-Strasse 24, Tulln, A-3430, Austria
3 – Bavarian Polymer Institute and Department of Chemistry, University of Bayreuth, Bayreuth, D-95440, Germany
4 – VTT – Technical Research Centre of Finland, Tietotie 4E, P.O. Box 1000, Espoo, FI-02044, Finland
5 – Lenzing AG, Werkstrasse 2, Lenzing, A-4860, Austria
6 – The Bioproducts Institute, Department of Chemical and Biological Engineering, and Department of Chemistry and Wood Science, University of British Columbia, 2360 East Mall, Vancouver, BC, V6T 1Z4, Canada

Published in: Small, 2020, Vol. 16, Issue 50, 2004702
DOI: 10.1002/smll.202004702


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