Copper (Cu)-Silica Nanocomposite Containing Valence-Engineered Cu: A New Strategy for Improving the Antimicrobial Efficacy of Cu Biocides

    Authors

    M. Young;S. Santra

    Comments

    Authors: contact us about adding a copy of your work at STARS@ucf.edu

    Abbreviated Journal Title

    J. Agric. Food Chem.

    Keywords

    copper; silica; antimicrobial; mixed-valence; agricultural biocide; ESCHERICHIA-COLI; TOXICITY; ELECTRON; DNA; Agriculture, Multidisciplinary; Chemistry, Applied; Food Science &; Technology

    Abstract

    Copper (Cu) compounds are widely used as antibacterial/antifungal agents for protecting food crops. Prolonged use of Cu biocides would lead to undesirable Cu levels in agricultural soil. In the absence of a suitable alternative, prudent use of Cu biocides is required. This paper reports for the first time a composite material of sol gel silica host matrix loaded with mixed-valence Cu as an alternative to conventional biocides. In this composite material, Cu is present in different oxidation states. The hydrophilic silica matrix serves as a water-dispersible delivery vehicle for antimicrobial Cu. It is hypothesized that a mixed-valence Cu system, specifically enriched with Cu(0) and Cu(I), will exhibit enhanced antimicrobial efficacy over traditional Cu(II) compounds. Materials were characterized by high-resolution transmission electron microscopy and X-ray photoelectron spectroscopy for the determination of particle size, morphology, crystallinity, and Cu oxidation states. Antimicrobial studies against Xanthomonas alfalfae and Escherichia coli (minimum inhibitory concentration) showed improved efficacy in MV-CuSiNG treatment compared to CuSiNG and other controls. Phytotoxicity studies performed (in Vinca sp. and Hamlin orange) under greenhouse conditions showed that the newly prepared nanocomposite is safe for plants, demonstrating potential usefulness of the material in agricultural biocides.

    Journal Title

    Journal of Agricultural and Food Chemistry

    Volume

    62

    Issue/Number

    26

    Publication Date

    1-1-2015

    Document Type

    Article

    Language

    English

    First Page

    6043

    Last Page

    6052

    WOS Identifier

    WOS:000338692900002

    ISSN

    0021-8561

    Share

    COinS