Combining an optical resonance biosensor with enzyme activity kinetics to understand protein adsorption and denaturation

    Authors

    K. A. Wilson; C. A. Finch; P. Anderson; F. Vollmer;J. J. Hickman

    Comments

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    Abbreviated Journal Title

    Biomaterials

    Keywords

    Biosensor; Modeling; Protein adsorption; Surface modification; Nanobiotechnology; Self-assembled monolayer; QUARTZ-CRYSTAL MICROBALANCE; INDUCED CONFORMATIONAL-CHANGES; WHISPERING-GALLERY MODES; HIGH-Q MICROCAVITIES; GLUCOSE-OXIDASE; ASPERGILLUS-NIGER; SOLID-SURFACES; THIN-FILMS; SHIFT; MICROSPHERES; Engineering, Biomedical; Materials Science, Biomaterials

    Abstract

    Understanding protein adsorption and resultant conformation changes on modified and unmodified silicon dioxide surfaces is a subject of keen interest in biosensors, microfluidic systems and for medical diagnostics. However, it has been proven difficult to investigate the kinetics of the adsorption process on these surfaces as well as understand the topic of the denaturation of proteins and its effect on enzyme activity. A highly sensitive optical whispering gallery mode (WGM) resonator was used to study a catalytic enzyme's adsorption processes on different silane modified glass substrates (plain glass control, DETA, 13F, and SiPEG). The WGM sensor was able to obtain high resolution kinetic data of glucose oxidase (GO) adsorption with sensitivity of adsorption better than that possible with SPR. The kinetic data, in combination with a functional assay of the enzyme activity, was used to test hypotheses on adsorption mechanisms. By fitting numerical models to the WGM sensograms for protein adsorption, and by confirming numerical predictions of enzyme activity in a separate assay, we were able to identify mechanisms for GO adsorption on different alkylsilanes and infer information about the adsorption of protein on nanostructured surfaces. (C) 2014 Elsevier Ltd. All rights reserved.

    Journal Title

    Biomaterials

    Volume

    38

    Publication Date

    1-1-2015

    Document Type

    Article

    Language

    English

    First Page

    86

    Last Page

    96

    WOS Identifier

    WOS:000347276300009

    ISSN

    0142-9612

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