Carbon-Dot Initiated Synthesis of Polypyrrole and Polypyrrole@CuO Micro/Nanoparticles with Enhanced Antibacterial Activity

The carbon dot initiated polypyrrole (PPY) and CuO composite were synthesized into PPY@CuO using a simple one-step sonochemical approach. The synthesized PPY and the PPY@CuO were characterized using Fourier-transform infrared spectroscopy, thermogravimetric analysis, X-ray diffraction, 13C-solid-state nuclear magnetic resonance (NMR) spectroscopy, UV–visible spectroscopy, and scanning electron microscopy. A strong interaction was demonstrated between the PPY chains and CuO. This interaction led to changes in the backbone chain of the PPY@CuO composite when compared to the carbon dot initiated PPY. The antibacterial activity against Escherichia coli and Staphylococcus aureus of the carbon dot initiated synthesis of PPY and the sonochemically prepared PPY@CuO composite materials was revealed. The results indicate the biocidal efficacy of PPY@CuO on both Gram-positive and Gram-negative bacteria. The PPY@CuO composite exhibited an enhanced antibacterial performance in comparison with the carbon dot initiated PPY and CuO. This is a first report on the sonochemical synthesis of a polymer composite composed of PPY and CuO, demonstrating the efficacy of its antibacterial action at a concentration of 1 mg/mL of the composite involving 0.234 mg/mL of CuO.