Viral aerosol control.

Viral concentration (PFUs) quantified from the agar plates is almost the same as the initial viral suspension. (TIF)</p

Surrogate virus inactivation.

(A) Representative figures of PFU/mL determination in on-contact droplet assays after different incubation times (0.5–24 h) with or without the AgCu nanolayer. It is shown results spotting serial dilution of PaMx60 on its bacteria host strain. Each experiment was performed in triplicate and spotting three times each serial dilution. (B) Time evolution of the viral inactivation percentage due to contact with the AgCu nanolayer.</p

Bacteria aerosol control.

Bacteria concentration (CFUs) quantified from the agar plates is almost the same as the initial bacterial suspension. (TIF)</p

Representative figures of bacterial growth on agar plates after 24 h on-contact with or without the AgCu nanolayer.

Representative figures of bacterial growth on agar plates after 24 h on-contact with or without the AgCu nanolayer.</p

Control experiment.

Control experiment to illustrate that the extracts obtained from the uncoated and coated PP do not affect the bacteria host from the surrogate viruses. A. Bacterial mat using only culture media. B. Bacterial mat adding the extracts. C Representative image of the bacteria lysis using the surrogate viruses. (TIF)</p

Bacteria on-contact droplet analysis.

The inhibition percentage due to contact with the AgCu nanolayer vs. PP using Eq 3. Each experiment was performed in triplicate and spotting three times each serial dilution.</p

Schematic figure showing the double-layer plaque assay technique for propagation of bacteriophages.

Schematic figure showing the double-layer plaque assay technique for propagation of bacteriophages.</p

Viral and bacterial aerosol supporting information.

Viral and bacterial aerosol supporting information.</p

Infectivity titre supporting information.

The transmission of bacteria and respiratory viruses through expelled saliva microdroplets and aerosols is a significant concern for healthcare workers, further highlighted during the SARS-CoV-2 pandemic. To address this issue, the development of nanomaterials with antimicrobial properties for use as nanolayers in respiratory protection equipment, such as facemasks or respirators, has emerged as a potential solution. In this study, a silver and copper nanolayer called SakCu® was deposited on one side of a spun-bond polypropylene fabric using the magnetron sputtering technique. The antibacterial and antiviral activity of the AgCu nanolayer was evaluated against droplets falling on the material and aerosols passing through it. The effectiveness of the nanolayer was assessed by measuring viral loads of the enveloped virus SARS-CoV-2 and viability assays using respiratory surrogate viruses, including PaMx54, PaMx60, PaMx61 (ssRNA, Leviviridae), and PhiX174 (ssDNA, Microviridae) as representatives of non-enveloped viruses. Colony forming unit (CFU) determination was employed to evaluate the survival of aerobic and anaerobic bacteria. The results demonstrated a nearly exponential reduction in SARS-CoV-2 viral load, achieving complete viral load reduction after 24 hours of contact incubation with the AgCu nanolayer. Viability assays with the surrogate viruses showed a significant reduction in viral replication between 2–4 hours after contact. The simulated viral filtration system demonstrated inhibition of viral replication ranging from 39% to 64%. The viability assays with PhiX174 exhibited a 2-log reduction in viral replication after 24 hours of contact and a 16.31% inhibition in viral filtration assays. Bacterial growth inhibition varied depending on the species, with reductions ranging from 70% to 92% for aerobic bacteria and over 90% for anaerobic strains. In conclusion, the AgCu nanolayer displayed high bactericidal and antiviral activity in contact and aerosol conditions. Therefore, it holds the potential for incorporation into personal protective equipment to effectively reduce and prevent the transmission of aerosol-borne pathogenic bacteria and respiratory viruses.</div

ESKAPE bacteria on-contact droplet analysis.

Time evolution of the bacterial inhibition percentage due to contact with the AgCu nanolayer vs. PP using Eq 3.</p