A nanofilter composed of carbon nanotube-silver composites for virus removal and antibacterial activity improvement

We have developed a new nanofilter using a carbon nanotube-silver composite material that is capable of efficiently removing waterborne viruses and bacteria. The nanofilter was subjected to plasma surface treatment to enhance its flow rate, which was improved by approximately 62%. Nanoscale pores were obtained by fabricating a carbon nanotube network and using nanoparticle fixation technology for the removal of viruses. The pore size of the nanofilter was approximately 38 nm and the measured flow rate ranged from 21.0 to 97.2 L/(min·m2) under a pressure of 1–6 kgf/cm2 when the amount of loaded carbon nanotube-silver composite was 1.0 mg/cm2. The nanofilter was tested against Polio-, Noro-, and Coxsackie viruses using a sensitive real-time polymerase chain reaction assay to detect the presence of viral particles within the outflow. No trace of viruses was found to flow through the nanofilter with carbon nanotube-silver composite loaded above 0.8 mg/cm2. Moreover, the surface of the filter has antibacterial properties to prevent bacterial clogging due to the presence of 20-nm silver nanoparticles, which were synthesized on the carbon nanotube surface.

Graphical abstractThe results of the removal test of a mixture solution containing Poliovirus and Norovirus. A filtration test showed that only the signals of the internal positive control (IPC) and not those of the Poliovirus and Norovirus, were amplified. Accordingly, the filtration experiment conducted on the mixture solution of Poliovirus and Norovirus confirmed that the viruses did not pass through the CNT-Ag nanofilter.Figure optionsDownload full-size imageDownload as PowerPoint slide