Inactivation of SARS-CoV-2 and Other Human Coronaviruses Aided by Photocatalytic One-Dimensional Titania Nanotube Films as a Self-Disinfecting Surface

Abstract

SARS-CoV-2 and its variants that continue to emerge have necessitated the implementation of effective disinfection strategies. Developing self-disinfecting surfaces can be a potential route for reducing fomite transmissions of infectious viruses. We show the effectiveness of TiO2 nanotubes (T_NTs) on photocatalytic inactivation of human coronavirus, HCoV-OC43, as well as SARS-CoV-2. T_NTs were synthesized by the anodization process, and their impact on photocatalytic inactivation was evaluated by the detection of residual viral genome copies (quantitative real-time quantitative reverse transcription polymerase chain reaction) and infectious viruses (infectivity assays). T_NTs with different structural morphologies, wall thicknesses, diameters, and lengths were prepared by varying the time and applied potential during anodization. The virucidal efficacy was tested under different UV-C exposure times to understand the photocatalytic reaction’s kinetics. We showed that the T_NT presence boosts the inactivation process and demonstrated complete inactivation of SARS-CoV-2 as well as HCoV-OC43 within 30 s of UV-C illumination. The remarkable cyclic stability of these T_NTs was revealed through a reusability experiment. The spectroscopic and electrochemical analyses have been reported to correlate and quantify the effects of the physical features of T_NT with photoactivity. We anticipate that the proposed one-dimensional T_NT will be applicable for studying the surface inactivation of other coronaviruses including SARS-CoV-2 variants due to similarities in their genomic structure.

Boosting Membrane Interactions and Antimicrobial Effects of Photocatalytic Titanium Dioxide Nanoparticles by Peptide Coating

“…From a wider perspective, we note that the approach taken in the present study to boost the antimicrobial effect by promoting proximity between bacteria and antimicrobial nanoparticles may also have a bearing also for other pathogens, other types of nanoparticles, and even other biological questions. For example, photocatalytic nanoparticles have been found to display potent antiviral effects on illumination, [8,9,74,75] hence surface modifying these with compounds having an affinity for virus capsids or capsid envelopes, such as aptamers, antiviral peptides, or antibodies toward capsid proteins may offer a way to boost antiviral effects of photocatalytic nanoparticles without simultaneously increasing cell toxicity. Indeed, this is supported by findings by Hu et al, who immobilized aptamers to GO and found this to promote virus binding and result in boosted inactivation of bacteriophage MS2 via oxidative damage under illumination.…”

Can photocatalysis help in the fight against COVID-19 pandemic?

“… Photocatalyst Light used for activation Tested microorganisms Efficiency Ref. TiO 2 /Ti photocatalyst coatings formed on Al 2 O 3 balls UV (black light fluorescent lamp) SARS-CoV-2 and influenza virus 99.96% inactivation rate for influenza virus and 99.99% inactivation rate for SARS-Co-V-2 in 120 min [ 31 ] Copper oxide grafted with titania (Cu x O/TiO 2 ) Indoor-light-white fluorescence bulb passed through a UV cutoff filter SARS-CoV-2 Denaturalization of spike proteins and fragmentation of RNAs in the SARS-CoV-2 virus in the dark enhanced by irradiation [ 32 ] WO 3 /Cu LED light (1000 lx) SARS-CoV-2, the WK-521 Complete inactivation in 4 h [ 33 ] TiO 2 nanotubes UV-C illumination HCoV-OC43, as well as SARS-CoV-2 Complete inactivation within 30 s [ 34 ] g-C 3 N 4 -based photocatalysts Visible-light irradiation E. coli and MS2 8-log inactivation during 240 min [ 35 , 36 ] AgNPs@TiO 2 UVA and LED SARS-CoV-2 Light intensity dependent activity; complete inactivation (initial Log PFU/cm 2 = 3.079) at 0.25-mW/cm 2 UV [ 37 ] TiO 2 (P25)–SiO 2 -coated PET Film Fluorescent light SARS-CoV-2 0.2-log reduction after 3 h [ 38 ] UV 2.5-log inactivation after 6.5 g-C 3 N 4 /Ag 2 CrO 4 Visible light (LED) SARS-CoV-2 spike protein 77.5% decomposed within 30 min [ 39 ] Cu x O/TiO 2 Visible li...…”

Rapid In Situ Thermal Decontamination of Wearable Composite Textile Materials

“…Recent methods of dry heat decontamination have focused on integrating heat-generating elements into the PPE material itself. Nanomaterials, such as graphene, molybdenum disulfide (MoS 2 ), and titania (TiO 2 ), have been embedded into material layers to perform localized photothermal heating for the inactivation of viral and bacterial contaminants. – In another approach, a copper mesh was employed in a mask to perform Joule heating for the thermal inactivation of viruses . Similarly, a layer of graphene was deposited onto a mask for use with a battery to provide portable Joule heating for the inactivation of viral contaminants .…”