Ultrasmall Gold Nanospheres Engineered with Nisin Pectin Bioconjugate: A Multifunctional Solution for Dye Removal, Detoxification, and Antimicrobial Applications

Contamination of water sources with effluents like toxic dye molecules, organophosphorus (OP) compounds, and pathogenic bacteria is a major public concern, since those contaminants cause serious health problems in humans, animals, and plants. Thus, there is an urgent need for solutions to clean water sources from toxic and harmful pollutants. Gold nanoparticles exhibit remarkable potential for the remediation of contaminated water sources due to their essential catalytic and antimicrobial attributes. Nevertheless, the existing synthesized gold nanoparticles have not yet achieved the desired triple-action capability of simultaneously eliminating toxic dye molecules, organophosphorus (OP) compounds, and pathogenic bacteria. To address this challenge, we designed ultrasmall gold nanospheres that incorporate a bioconjugate of nisin antimicrobial peptide and pectin (NisPec). The resulting nanoparticles, termed AuNP@NisPec, demonstrated the ability to generate reactive oxygen species (ROS), facilitating the decolorization and detoxification of harmful dye molecules. The synergistic relationship between the gold nanospheres and the NisPec polymer allowed these nanoparticles to hydrolyze the phosphoester bond, rendering them a potential solution for OP toxicity. Additionally, the NisPec-decorated gold nanospheres exhibited antimicrobial activity against both Gram-positive and Gram-negative bacteria. This innovative approach offers a comprehensive and holistic solution to address water contamination by simultaneously tackling multiple challenges.