Nanocoatings: Universal antiviral surface solution against COVID-19

Abstract

In the current scenario, there is critical global demand for the protection of daily handling surfaces from the viral contamination to limit the spread of COVID-19 infection. The nanotechnologists and material scientists offer sustainable solutions to develop antiviral surface coatings for various substrates including fabrics, plastics, metal, wood, food stuffs etc. to face current pandemic period. They create or propose antiviral surfaces by coating them with nanomaterials which interact with the spike protein of SARS-CoV-2 to inhibit the viral entry to the host cell. Such nanomaterials involve metal/metal oxide nanoparticles, hierarchical metal/metal oxide nanostructures, electrospun polymer nanofibers, graphene nanosheets, chitosan nanoparticles, curcumin nanoparticles, etched nanostructures etc. The antiviral mechanism involves the repletion (depletion) of the spike glycoprotein that anchors to surfaces by the nanocoating and makes the spike glycoprotein and viral nucleotides inactive. The nature of interaction between the nanomaterial and virus depends on the type nanostructure coating over the surface. It was found that functional coating materials can be developed using nanomaterials as their polymer nanocomposites. The various aspects of antiviral nanocoatings including the mechanism of interaction with the Corona Virus, the different type of nanocoatings developed for various substrates, future research areas, new opportunities and challenges are reviewed in this article.

Keywords: Antiviral coating; Covid-19; Nanomaterials; SARS-CoV-2.

Graphical abstract

Fig. 1

Larger droplets with viral content deposit close to the emission point (droplet transmission), while smaller droplets can travel several meters long in the air indoors (airborne transmission) .

Fig. 2

The structure of corona virus .

Fig. 3

a. The effects of different concentrations of CCM-CDs on Vero cells viability were detected by CCK-8 assay; b) the titer of PEDV when exposed or unexposed to 125 μg/mL EDA-CDs or CCM-CDs .

Fig. 4

The filtering capacity of commercial mask; outer layer filters respiratory droplets and middle layer filters droplet nuclei and fine dust.

Fig. 5

Scheme for proposed face masks with electrospun nylon-6 nanofibers on needle-punched nano PE substrate, (b) a photograph of the face mask .

Fig. 6

(a) Deposition process of GNEC film, the GNEC film was deposited on silicon substrate. (b) Fabrication process of the GNEC mask. (I) The deposited GNEC film with vertically grown graphene nanosheets with the thickness of 70 nm. (II) GNEC film was broken by high-frequency vibration. (III) Ultrasonic-extrusion of GNEC film with 40 kHz and 600 W, the GNEC fragment was uniformly distributed between the melt-blown fibers. (IV) A three-dimensional diagram of the finished GNEC mask .

Fig. 7

a) Schematic illustration of the inactivation of the virus in respiratory droplets through photothermal, photocatalytic, and hydrophobic self-cleaning processes after solar irradiation of the photoactive mask (PAM). b) Representative transmission electron microscope images of virus-like particles (VLPs) after treatment on the pristine surgical mask (left) and PAM (right) .

Fig. 8

(a-c) Low magnification SEM of ZnO NF decorated cotton cloth. (d) High magnification SEM shows the self-assembled petal like structures of a single nanoflower (e-g) SEM of bare cotton cloth showing the constituent cellulose fibers. (h) Schematic representation of the ZnO NF as observed under SEM .

Fig. 9

a) Individual packages of the wet wipes loaded with the silver nanoparticles, and b) antimicrobial and antiviral winter sweater made of cotton yarns treated with AgNPs .

Fig. 10

a) Transparency of dip-coated tempered mobile screen and b) SEM image of Cu–graphene composite sample .

Fig. 11

Scanning electron micrographs of the (A) smooth control Al (scale bar = 1 μm) and (B) etched Al (scale bar = 200 nm) with nanostructured topography (C) Viability of SARS-CoV-2 on the surfaces of the etched (nanostructured) Al 6063 alloy, control Al 6063 alloy and nonmetal surface tissue culture plates (TCP) at different time intervals of 1, 3, 6, 24, and 48 h. The titers of viable viruses are expressed as TCID₅₀/mL in logarithmic scale .

Fig. 12

(a) Schematic representation of a polyelectrolyte multilayer (PEM) film buildup by successive adsorption steps of polycations and polyanions followed by rinsing steps using the dipping method. (b) Three main strategies were followed to design antimicrobial PEM: antiadhesive films inhibiting the close approach of pathogens, contact killing films by exposing antimicrobial agents on the surface, and release-killing films delivering antimicrobial agents in the supernatant, with the last two strategies leading to the death of pathogens .

Fig. 13

Curcumin decorated cellulose nanocrystals derive from vegetable wastes and natural herbs can make use in generating antiviral edible coating for fruits and vegetables.