Transparent ‘nanosheets’ inactivate wide range of viruses and bacteria

From electronics to hydrogen storage, hydrogen boride (HB) ‘nanosheets’ – two-dimensional nanomaterials – have been suggested for a number of potential uses since they were first reported eight years ago. They could also have a further, unexpected application, according to new research – helping to prevent future pandemics.

The global fight against infectious disease faces two major challenges: the threat of new outbreaks and the alarming rise of antimicrobial resistance driven by excessive use of antibiotics. As pathogens evolve and spread, researchers are urgently seeking innovative technologies that could effectively combat viruses, bacteria and fungi in everyday settings.

New research from the Institute of Science in Tokyo explored interactions between biomolecules and HB nanosheets, first invented by Professor Takahiro Kondo and his team at the University of Tsukuba. The new work, which involved Professor Kondo and colleagues, discovered that HB nanosheets exhibit “excellent” antibacterial, antiviral and antifungal properties. The nanomaterial has a “remarkable ability” to inactivate a wide range of pathogens, according to a research announcement.

The team first fabricated transparent films by coating glass substrates with a dispersed solution of HB nanosheets. They then tested these films against a wide variety of microorganisms. “Remarkably, the coated surfaces exhibited exceptional antimicrobial performance, inactivating the SARS-CoV-2 [coronavirus], influenza, and feline caliciviruses down to detection limits within just 10 minutes at room temperature, without the need for light activation,” the announcement said.

Similar effects were observed against various bacteriophages, multiple types of bacteria, such as E. coli and Staphylococcus aureus, and fungi, such as Aspergillus niger and Penicillium pinophilum.

The group investigated the underlying mechanisms behind the broad-spectrum antimicrobial activity, finding that it originates from the nanosheets’ ability to denature microbial proteins through strong physicochemical interactions.

“What makes these findings particularly exciting is the versatility of HB nanosheets as transparent coating materials. Unlike metal-based antimicrobials, which may leach or lack transparency, and photocatalyst-based coatings that require ultraviolet light activation, HB nanosheets function effectively in darkness and maintain optical clarity,” the researchers said.

Laboratory tests further demonstrated their effectiveness under dry conditions, mimicking real-world scenarios where pathogens might be transferred by coughing or sneezing onto everyday surfaces.

HB nanosheets could be applied as transparent coatings on items and textiles to reduce infection risks, the team said, as well as other materials found in everyday settings.

The work was published online in Journal of Materials Chemistry B.

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