Synergistic Antiviral Effects of Metal Oxides and Carbon Nanotubes

In this research, the synergistic antiviral effects of carbon nanotubes (CNTs) and metal oxides (MO) in the form of novel hybrid structures (MO-CNTs) are presented. Raw CNTs, Ni(OH)₂, Fe₂O₃ and MnO₂, as well as Ni(OH)₂-CNT, Fe₂O₃-CNT and MnO₂-CNT were explored in this study against Escherichia. coli MS2 bacteriophage, which was used as a virus surrogate. The nano particles were synthesized and characterized using field emission scanning electron microscopy (FESEM), energy-dispersive X-ray spectroscopy (EDS), transmission electron microscopy (TEM), particle size analysis, Fourier-transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD). Kinetic parameters such as the LD₅₀ (lethal dose to kill 50% of the population), T₅₀ and T₈₀ (time taken to kill 50% and 80% of the population), SGR (specific growth rate) and IRD (initial rate of deactivation of the population) were also studied to examine the antiviral efficacy of these nanomaterials. Among all the nanomaterials, Ni(OH)₂-CNT was the most effective antiviral agent followed by Fe₂O₃-CNT, MnO₂-CNT, raw CNTs, Ni(OH)₂, Fe₂O₃ and MnO₂. When comparing the metal oxide-CNTs to the raw CNTs, the average enhancement was 20.2%. The average antiviral activity enhancement of the MO-CNTs were between 50 and 54% higher than the MO itself. When compared to the raw CNTs, the average enhancement over all the MO-CNTs was 20.2%. The kinetic studies showed that the LD₅₀ of Ni(OH)₂-CNT was the lowest (16µg/mL), which implies that it was the most toxic of all the compounds studied. The LD₅₀ of Ni(OH)₂, Fe₂O₃ and MnO₂ were 17.3×, 14.5× and 10.8× times greater than their corresponding hybrids with the CNTs. The synergistic mechanism involved the entrapment of phage viruses by the nano structured CNTs leading to structural damage along with toxicity to phage from the release of MO ions. The metal oxide-CNT nano hybrids developed in this project are promising candidates in applications such as antiviral coatings, nanocomposites, adsorbents and as components of personal protection gears.