LAUSR

Abstract The antiviral properties of nanocarbons namely, carbon nanotubes (CNT), graphene oxide (GO), reduced graphene oxide (rGO), hybrid GO-CNT, rGO-CNT and CNTs functionalized with carboxylic (CNT-COOH), phenol (CNT-phenol), silver (CNT-Ag) are presented. Escherichia coli MS2 bacteriophage was the model virus. All the nanocarbons showed antiviral activities and the activity increased with increase in concentration. CNT-phenol showed the highest antiviral activity (97.1%) at 0.3 mg/mL followed by CNT-Ag (90%), GO-CNT (85.5%), rGO-CNT (83.5%), CNT-COOH (82.5%), CNT (78%), GO (45.6%) and rGO (39.5%) at the same concentration. At 0.05 mg/ml, compared to pure CNTs, those functionalized with silver and phenol showed 270% and 200% higher removal efficiencies respectively. GO and rGO were less efficient by themselves, but with the CNTs, namely GO-CNT and rGO-CNT, their activities enhanced by factors of 650 and 950% respectively. The ED50, defined as the effective dose that produces a specific effect in 50% of the population, was as low as 0.006 µg/mL for CNT-Phenol, which was 1700 times small than pure CNTs. From transmission electron microscopy (TEM) analysis, it was observed that the CNTs entangle the viruses which probably led to physical damage of the viral structure while the functional groups attached to CNTs such as phenol and Ag further enhanced toxicity due to their own properties.