Photodynamic Activity of Graphene Oxide/Polyaniline/Manganese Oxide Ternary Composites toward Both Gram-Positive and Gram-Negative Bacteria.
Gustavo ChataForrest NicholsRene MercadoTufa AssafaGlenn L MillhauserChad SaltikovShaowei ChenPublished in: ACS applied bio materials (2021)
Graphene derivatives have been attracting extensive interest as effective antimicrobial agents. In the present study, ternary nanocomposites are prepared based on graphene oxide quantum dots (GOQD), polyaniline (PANI), and manganese oxides. Because of the hydrophilic GOQD and PANI, the resulting GPM nanocomposites are readily dispersible in water and upon photoirradiation at 365 nm exhibit antimicrobial activity toward both Gram-negative Escherichia coli ( E. coli ) and Gram-positive Staphylococcus epidermidis ( S. epidermidis ). Notably, the nanocomposite with a high Mn 2+ and Mn 4+ content is found to be far more active than that with a predominant Mn 3+ component, although both samples feature a similar elemental composition and average Mn valence state. The bactericidal activity is largely ascribed to the photocatalytic production of hydroxy radicals and photogenerated holes; both are known to exert oxidative stress on bacterial cells. Further antimicrobial contributions may arise from the strong affinity of the nanocomposites to the cell surfaces. These results suggest that the metal valence state may be a critical parameter in the design and engineering of high-performance antimicrobial agents based on metal oxide nanocomposites.
Keyphrases
- reduced graphene oxide
- gram negative
- biofilm formation
- staphylococcus aureus
- escherichia coli
- multidrug resistant
- gold nanoparticles
- room temperature
- oxidative stress
- induced apoptosis
- quantum dots
- transition metal
- visible light
- metal organic framework
- carbon nanotubes
- pseudomonas aeruginosa
- candida albicans
- single cell
- oxide nanoparticles
- machine learning
- deep learning
- dna damage
- photodynamic therapy
- endoplasmic reticulum stress
- signaling pathway
- liquid chromatography
- ionic liquid
- bone marrow
- cell cycle arrest
- cystic fibrosis
- drug delivery
- high resolution
- walled carbon nanotubes