(a) Antiviral activity of prepared powders against coronavirus. (b and c) Photos showing the change in plaque number of coronavirus after four hours: (b) control and (c) with CMO. Image: Material Letters.
(a) Antiviral activity of prepared powders against coronavirus. (b and c) Photos showing the change in plaque number of coronavirus after four hours: (b) control and (c) with CMO. Image: Material Letters.

Researchers at the Tokyo Institute of Technology in Japan, working in collaboration with colleagues at the Kanagawa Institute of Industrial Science and Technology and the Nara Medical University, also in Japan, have succeeded in preparing a material called cerium molybdate (γ-Ce2Mo3O13; CMO), which exhibits high antiviral activity against coronavirus. The researchers report their work in a paper in Materials Letters.

The ongoing coronavirus pandemic has highlighted the urgency not only of vaccine development and rollout, but also of developing innovative materials and technologies with antiviral properties that could play a vital role in helping to contain the spread of the virus. Conventional inorganic antimicrobial materials are often prepared with metals such as copper or photocatalysts such as titanium dioxide. But metal-based materials can be prone to corrosion, while the effects of photocatalysts are understandably limited under dark conditions.

Now, a research team led by Akira Nakajima in Tokyo Institute of Technology's Department of Materials Science and Engineering proposes a new type of an antiviral material that can overcome these drawbacks. The team successfully combined cerium (Ce), a relatively low-cost rare earth element, with molybdenum (Mo), which is well known for its antibacterial effects, to prepare two types of cerium molybdate (Ce2Mo3O12 and γ-Ce2Mo3O13) in powder form.

Both powders exhibited antiviral activity against a bacteriophage that acts as a model for viruses with lipid envelopes, known as envelope-type viruses, while γ-Ce2Mo3O13 also exhibited high antiviral activity against SARS-CoV-2, the virus that causes covid-19. The researchers propose that an effective combination of cerium with the molybdate ion, as well as the comparatively large surface area offered by the powder, are key factors contributing to the observed antiviral activity.

This study builds on earlier work led by Nakajima, which demonstrated the antiviral activity of a material named LMO (La2Mo2O9), composed of lanthanum (La) oxide and molybdenum oxide. But LMO's activity was found to be better against non-envelope-type viruses than envelope-type viruses.

Subsequent tests showed that incorporating cerium into this material to make La1.8Ce0.2Mo2O9 (LCMO) improved the antiviral activity against envelope-type viruses. It was this remarkable finding that spurred further investigation into cerium molybdates (CMO) as promising materials with high antiviral activity against envelope-type viruses such as influenza and SARS-CoV-2.

To obtain CMO powder samples with an almost single-crystal phase, the team conducted many trial experiments before successfully preparing Ce2Mo3O12 using the polymerizable complex method and γ-Ce2Mo3O13 through hydrothermal processing.

If standardized and mass-produced, CMO could find use in a wide range of materials, such as resins, paper, thin films and paints. This would open up the possibility of using CMO coatings for high-contact surfaces like door handles, straps inside vehicles, elevator buttons and escalator belts, as well as walls, tiles and windows.

Nakajima envisions that materials incorporating CMO could also be used in everyday items such as smartphones and clothing. He notes that applications for eye- and face-ware such as glasses and masks may take a little longer to develop, but could also be on the horizon.

This story is adapted from material from the Tokyo Institute of Technology, with editorial changes made by Materials Today. The views expressed in this article do not necessarily represent those of Elsevier. Link to original source.