Bioactive Ag₃PO₄/Polypropylene Composites for Inactivation of SARS-CoV-2 and Other Important Public Health Pathogens

Abstract

The current unprecedented coronavirus pandemic (COVID-19) is increasingly demanding advanced materials and new technologies to protect us and inactivate SARS-CoV-2. In this research work, we report the manufacture of Ag 3 PO 4 (AP)/polypropylene (PP) composites using a simple method and also reveal their long-term anti-SARS-CoV-2 activity. This composite shows superior antibacterial (against Staphylococcus aureus and Escherichia coli ) and antifungal activity (against Candida albicans ), thus having potential for a variety of technological applications. The as-manufactured materials were characterized by XRD, Raman spectroscopy, FTIR spectroscopy, AFM, UV–vis spectroscopy, rheology, SEM, and contact angle to confirm their structural integrity. Based on the results of first-principles calculations at the density functional level, a plausible reaction mechanism for the initial events associated with the generation of both hydroxyl radical • OH and superoxide radical anion • O 2 – in the most reactive (110) surface of AP was proposed. AP/PP composites proved to be an attractive avenue to provide human beings with a broad spectrum of biocide activity.

Effect of Surface Porosity on SARS-CoV-2 Fomite Infectivity

“…The observed dependence of the stability of SARS-CoV-2 on different materials , suggests that materials can be specifically developed to reduce the lifetime of SARS-CoV-2 on solids. Coatings are particularly attractive because they can be applied to a variety of different objects with a low amount of active material, and this idea has stimulated the fabrication of antiviral coatings. − To date, surface coatings of copper , and its two oxide forms, ,− silver oxide, zinc oxide, and light-activated titanium dioxide have shown promising results for practical application on common touch surfaces with a high frequency of contacts. Moreover, silver , and zinc species , have also accelerated the inactivation of this virus.…”

Polypropylene Modified with Ag-Based Semiconductors as a Potential Material against SARS-CoV-2 and Other Pathogens

“…In addition, this material proved to be particularly effective against the pathogenic microorganisms tested, without causing any type of dermatitis to its user. In other works, we were able to immobilize SiO 2 -Ag particles in different polymers, reaching over 99% viral clearance in just 15 min. , Very recently, we reported that the incorporation of Ag 3 PO 4 into a polymer matrix leads to a composite with antimicrobial action against SARS-CoV-2 and other opportunistic and potential pathogens …”

“…The elimination of these microorganisms (bacteria, fungi, and viruses) occurs due to the generation of reactive oxygen species (ROS) in the semiconductor, even in the dark. ,, When interacting with propylene groups, different semiconductors such as Ag 2 XO 4 (X = W, Mo, and Cr) can increase their electronic density in the conduction band (CB). This transfer of electrons (e – ) from polypropylene increases the reducing character of the semiconductor.…”

“…As a result, there is the release of a hole (h + ) that interacts with H 2 O through the formation of a hydroxyl radical (•OH) and a proton (H + ). On the other hand, the released H + in the valence band (VB) interacts with •O 2 – , which in turn reacts by forming the hydroperoxyl radical (•OOH) . In previous works, it was possible to identify through scavenger tests that these ROS are responsible for the antimicrobial and photocatalytic activity of α-Ag 2 WO 4 , β-Ag 2 MoO 4 , and Ag 2 CrO 4 . ,,, These ROS generated by Ag 2 XO 4 (X = W, Mo, and Cr) semiconductors can interact with lipids, nucleic acids, proteins, and other components, causing the death of these microorganisms .…”

“…3,35 Very recently, we reported that the incorporation of Ag 3 PO 4 into a polymer matrix leads to a composite with antimicrobial action against SARS-CoV-2 and other opportunistic and potential pathogens. 36 In this work, we discuss how the immobilization of silverbased semiconductors such as α-Ag 2 WO 4 , β-Ag 2 MoO 4 , and Ag 2 CrO 4 on PP provides a composite with improved antimicrobial activity. The antimicrobial activities were evaluated against Gram-positive (Staphylococcus aureus) and Gram-negative (Escherichia coli) bacteria, fungus (Candida albicans), and SARS-CoV-2 virus.…”