Unbound MEDLINE

A 3D localized surface plasmon resonance biosensor for the study of trivalent arsenic binding to the ArsA ATPase.

Abstract

A self-assembled 3D hydrogel-nanoparticle composite integrated surface plasmon resonance (SPR) sensor is reported here. The novel assembled substrate was developed by means of a surface mediated radical co-polymerization process to obtain a highly sensitive hydrogel-based thin film that possesses specific binding sites for target analytes. Initially, amino group modified gold nanoparticles (AuNPs) were covalently linked to acrylic acid monomer. Following this, N-isopropylacrylamide (NIPAAm) and AuNPs linked acrylic acid (AAc) monomers were randomly co-polymerized by the "grafting from" method in the presence of initiator and crosslinker onto the sensing surface. Surface characterization techniques were utilized to evaluate the thickness and composition of the hydrogel-nanoparticle film. The sensing platform was employed to study the binding kinetics and conformational changes of the ArsA ATPase as a consequence of binding trivalent arsenicals under a variety of conditions. ArsA, the catalytic subunit of the ArsAB arsenite (As(III)) translocating ATPase, is one of the five proteins encoded by the arsenical resistance (ars) operon of plasmid R773 in cells of Escherichia coli, that confers resistance to trivalent and pentavalent salts of the metalloid arsenic. SPR measurements indicate that the 3D hydrogel-nanoparticle coated sensors exhibited a higher sensitivity than that of the 2D AuNPs decorated sensors. Binding of As(III) to ArsA is greatly facilitated by the presence of magnesium ion and ATP.

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  • Publisher Full Text

    • Authors

    Liu C, Balsamo V, Sun D, Naja M, Wang X, Rosen B, Li CZ

    Institution

    Nanobioengineering/Nanobioelectronics Laboratory, Department of Biomedical Engineering, Florida International University, 10555 W Flagler Street, Miami, FL 33174, USA.

    Source

    Biosensors & bioelectronics 38:1 pg 19-26

    MeSH

    Adenosine Triphosphatases
    Arsenic
    Enzymes, Immobilized
    Escherichia coli
    Escherichia coli Proteins
    Gold
    Hydrogel
    Ion Pumps
    Multienzyme Complexes
    Nanoparticles
    Protein Binding
    Sensitivity and Specificity
    Surface Plasmon Resonance

    Pub Type(s)

    Evaluation Studies
    Journal Article
    Research Support, N.I.H., Extramural
    Research Support, Non-U.S. Gov't

    Language

    eng

    PubMed ID

    22658909