Antibody-Functionalized Copper Oxide Nanoparticles with Targeted Antibacterial Activity

Copper oxide nanoparticles (CuO-NPs) were functionalized with specific antibodies to target their antibacterial activity against Gram-positive or Gram-negative bacteria. The CuO-NPs were covalently functionalized to cover their surface with specific antibodies. The differently prepared CuO-NPs were characterized by X-ray diffraction, transmission electron microscopy and dynamic light scattering. The antibacterial activities of the unmodified CuO-NPs and the antibody-functionalized nanoparticles (CuO-NP-AbGram^- and CuO-NP-AbGram⁺ ) were determined for both Gram-negative Escherichia coli and Gram-positive Bacillus subtilis bacteria. The antibody-functionalized NPs showed a differential increase of their antibacterial activity according to the specific antibody. The CuO-NP-AbGram^- in E. coli showed reduced half maximal inhibitory concentration (IC₅₀ ) and minimum inhibitory concentration (MIC) values when compared with unfunctionalized CuO-NPs. On the other hand, the CuO-NP-AbGram⁺ also showed reduced IC₅₀ and MIC values in B. subtilis, when compared with non-functionalized CuO-NPs. Thus, the functionalized CuO nanoparticles with specific antibodies showed enhanced specificity of their antibacterial activity. The advantages of "smart" antibiotic nanoparticles are discussed.