Nano-sized Metal Oxides and Their use as a Surface Disinfectant Against COVID-19: (Review and Perspective)

Contamination of surfaces has long been identified as a significant factor in viral transmission. Therefore, sustained efforts are required to address this issue. This work aims to build a scientific database on nano-sized metal oxides as intelligent materials for surface disinfection against corona viruses, synthesize and characterize nano-sized MgO, and discuss the possibility of using it in virus eradication. The MgO nanoparticle was prepared through the heating method. Meanwhile, XRD diffractometer, Scan electron microscope, and nitrogen adsorption were used to characterize the MgO nanoparticle. The synthesized MgO nanoparticle showed an average crystallite size of 18.55nm, lattice strain 0.0053, surface area 27.56 m 2 /g and d-spacing 2.1092. The outcomes of this review highlight the advantage and challenges of AgO, CuO, ZnO, TiO 2 and MgO nanoparticles and their utilization for surface disinfection against coronaviruses.


INTRODUCTION
A novel coronavirus (SARS-CoV-2) was reported in Wuhan, the People's Republic of China, in December 2019. 1 Coronaviruses are a vast group of viral pathogens responsible for many diseases, including respiratory illness. 2 This disease can produce a variety of signs involving temperature, respiratory problems, sneezing and aggressive lung diseases. 3When viruses enter the lungs, they cause harm, which results in fluid seeping from tiny blood vessels in the lung tissue.The fluid gathers in the lungs' alveolar or air sacs.Because of this, the lungs have a tough time transferring oxygen from the air to the blood.It has the potential to extend to the lower respiratory tract, resulting in viral meningitis.Patients with severe breathlessness and breathing stress syndrome suffer from the condition. 4COVID-19 could be spread from person to person via the air, and in extreme cases, the incubation time might be up to 14 days or more. 5There are no clinical indications or symptoms to help identify those at risk, and the virus can be spread even during the incubation or recessive infection phase. 6Infection rates and fatalities have already overtaken SARS cases significantly in the same timeframe.Coronavirus is a sphere-shaped, encapsulated particle with a diameter of around 120nm produced by the virus.Several features of the viral life cycle are influenced by envelope proteins, including virus assembly, envelope development and pathogenesis. 7][10] According to current studies, the virus is more likely to spread amongst people near by. 11,12Tiny liquid particles can spread the virus when an infected person coughs, sneezes, talks, sings, or breathes. 13,147][28][29][30] In the past few decades, nanotechnology and nanostructured materials significantly assisted the progress of scientific and technological fields.The study of nanomaterials, including graphene, nanotubes, metal and polymer nanoparticles, has received much attention.Due to their smaller size (less than 100nm), these nanostructured materials display exceptional physical and chemical characteristics like higher molar extinction coefficients, superior reactivity, higher sorption and surface area, tunable plasmonic properties, photo and magnetic properties, and quantum effects.As a result, numerous nanomaterials have been examined extensively in various sectors.Significant focus has been placed in particular on the biomedical small molecule treatments have substantial drawbacks in human health applications, including poor photostability, non-biocompatibility, adverse effects on other organs, rapid renal clearance, a shorter blood fluid retention period, poor targeting, and insufficient cellular uptake.Nanomaterials were later created and studied.However, although they are superior to tiny molecules in some ways, their unregulated medicinal applications limit their use.In recent times, stimuli-responsive materials have been developed to address the current issues.0] The purpose of the present review is to establish a scientific baseline data of metallic nanocoating as intelligent materials for surface disinfection against bacteria and coronaviruses and introduce MgO nanoparticles as promising and prospects material for viral surface disinfectant.

Synthesis of nanoparticles MgO
An adequate amount of magnesium carbonate (MgCO 3 ) was loaded into a hollow cylindrical furnace and heated to 700 o C for one hour.The obtained white powder was characterized by employing various techniques to prove the MnO at the nanoscale level.

Nanoparticles characterization
T h e R i g a k u M i n i F l ex 6 0 0 X -ray diffractometer was utilized to acquire the XRD data.N 2 adsorption-desorption technique was employed to measure the surface area and pore size.The textural characteristics of the produced materials were examined using scanning electron microscopy (Phenom) Energy Dispersive X-ray (EDX) microanalysis combined with scanning electron was utilized to determine the elemental compositions of the samples.

COVID-19 and surfaces contamination
The National Institutes of Health (NIH) has proposed that healthy people might become infected with COVID-19 by contacting virus-infested surfaces. 424][45][46] However, studies demonstrate that the virus is less likely to spread three days after a person with COVID-19 contacts a common surface.4] There are already some protective tools available today.[57]

Nanotechnology and surfaces control against COVID-19
9][60] Nanomaterials are particles with sizes varying between 1 and 100 nanometers, allowing them to have many properties. 614][65] This is due to its high strength, lightweight, excellent chemical reactivity, minimal size, high surface area, and increased stability. 66

Metallic nanoparticles Titanium dioxide nanoparticles TiO 2
0] These features can be used in a variety of applications. 71Titanium oxide nanocrystals (TiO 2 ) are frequently employed in contemporary medicine because they exhibit significant antimicrobial and antiviral capabilities and the capacity to be used as drug delivery carriers [72][73] .
5] Metal nanoparticles are also used to improve nutritional supply, enhance meat productivity, improve milk and egg quality, and improve sperm function. 76Despite, TiO 2 nanoparticles being believed to be non-toxic in minimal quantities, cytotoxicity has been shown at large dosages. 77Because of their vast surface area, TiO 2 -NPs have a significant propensity to capture various toxic compounds.Exposure to TiO 2 -NPs inhibits development in certain animals and induces oxidative stress, damage, and disability. 78[81][82][83][84][85]

ZnO nanoparticle
Zinc oxide is one of the most widely used semiconducting materials in various fields such as flat displays, electroacoustic devices, and photocatalysts. 86Zinc oxide is a remarkable material with multiple properties suitable for high technology, such as light-emitting diodes, photodetectors, chemical and biological sensors and energy collectors; including solar cells. 87The use of nanozinc oxide was not limited to these areas only. 88till, it was an essential element in the medical field, especially in the last few years, where it witnessed a remarkable development in nanotechnology in medicine. 89Among the many semiconductors, metal oxides, especially zinc oxide, are biologically safe, cost-effective, and non-toxic medicine. 90[95][96]

Copper oxide nanoparticle CuO
CuO is a remarkable nanoscale material with various applications, including catalytic reactions, heating processes, superconductors, photovoltaic cells, chemical technology, gaseous sensors, and batteries.8] CuO employed in healthcare centers because of their antimicrobial properties, which allow them to eradicate over 99.9 percent of bacteria after 2 h of exposure if a sufficient dose is administered. 99Copper ions are antiviral substances and can be used to treat viruses such as herpesvirus, pneumonia, and hepatitis A. 100.Fur ther, compared to AgNPs and AuNPs, CuO NPs display numerous benefits, such as being less costly and stable.According to an investigation carried out by The National Institutes of Health (NIH) in the United States, the viral lifetime on Cu surfaces was less than on cardboard, stainless steel, and plastics surfaces. 101[104]

Silver oxide nanoparticles AgO
AgNPs have specific optical, electrical, and thermal characteristics and are employed in various products, including environmental, photovoltaics, sensors and industr y. [105][106] Furthermore, silver nanoparticles are increasingly used in antimicrobial coatings, different textiles, wound dressings, and biomedical equipment. 107ilver nanoparticles absorb and scatter light with incredible efficiency and their color changes with particle size and shape, unlike many dyes and pigments. 108The antimicrobial, antiviral, and immunological properties of AgNPs are wellestablished. 109AgNPs are a possible antiviral medication that is efficacious versus COVID-19 and other viral such as respiratory syncytial, HBV, and HIV [110][111] AgNPs can produce free radicals and reactive oxygen species (ROS), which cause apoptosis-mediated cellular damage and hence prevent virus replication. 112AgNPs bind to the viral genome, controlling the function and interaction of numerous viral and cellular replication components, leading to viral replication suppression and the release of progeny virions. 113urthermore, numerous physicochemical features, including size, morphology, surface characteristics, disparity, can be used to improve AgNPs-virus interactions. 114The use of silver nanoparticles is limited due to the high cost. 115

XRD diffraction patterns analysis of MgO
In accordance with the spectra, the samples have an excellent crystalline structure, with the highest peak position around 42.5 (2 theta) as shown in Fig. (2).The diffraction peaks might be associated to face-centered cubic structure of MgO (JCPDS card No: 78-0430).The XRD pattern revealed no impurities existence in the sample.The presence of nanostructures in the specimens was suggested by greatly expanded lines in the XRD pattern.The X-ray diffraction parameters of MnO nanoparticles including average crystallite size, lattice strain and d spacing were computed employing Debye-Scherer's equation.The average crystallite size was (18.55nm), lattice strain (0.0053) and d spacing (2.1092). 121

Morphological features of MgO
Figure 3 illustrates the morphological characteristics of MgO nanoparticles at various micrographs.The SEM analysis showed that the MgO nanoparticles seem to have an irregular shape; however, some of them look like coffee beans.The SEM images show that the obtained materials were in nanoscale form.The energy dispersive X-ray analysis shows the chemical composition of the MgO nanoparticle.

Nitrogen Adsorption Study of MgO
An investigation of nitrogen isotherms a n d t h e p o r e s i z e d i s t r i b u t i o n o f M g O nanopar ticles are described in the Figure (4 and 5).The absorption isotherm of MgO nanoparticles showed nanostructures feature according to the IUPAC categor ization of mesoporous oxide. 122The value of surface area, pore volume, and pore size of MgO nanoparticle are summarized in Table 1.

Virus elimination by metallic oxides nanoparticles
Metal nanoparticles have several uses, including disinfectants, due to their antiviral and antibacterial capabilities. 123Metallic particles such as as AgO, CuO, ZnO, TiO 2 and MgO, in contrast to alcohol-based sanitizers, which is ecologically beneficial, fireproof, and nonvolatile, are considered as clean technology 124 .6][127][128] This is extremely useful because the virus infects the host cell by introducing the virus's nucleic acid into the host cell following physical touch. 129erefore, sanitizer's metal-oxide nanoparticles offer enhanced safety and health features that might be effective towards COVID-19. 130The primary idea behind our study is to coat any material including, leather surface with AgO, CuO, ZnO, TiO 2 and MgO nanoparticles in order to eliminate Coronavirus. 131To adhere the AgO, CuO, ZnO, TiO 2 and MgO nanoparticles to the leather surface, a binder material was utilized.Metallic oxide NPs were then dispersed in an ethanol solution and distributed across the leather surface to produce a coating as shown Fig. (6).Various studies have been investigated the lifetime of SARS-CoV-2 on porous and non-porous surfaces. 1329] Therefore, coating nanomaterials such as AgO, CuO, ZnO, TiO 2 , and MgO with a particle size of fewer than 50 nanometers can stop the virus from penetrating surfaces.The average crystal size of MgO NPs nanoparticles in our investigation was 18.55 nm, indicating that MgO NPs have the potential to inhibit coronavirus. 140Some microscopic imaging investigations of bacterial cells and vir us proteomics data revealed that MgO nanoparticles caused membrane damage. 141ig. (7) presents the proposed mechanism of AgO, CuO, ZnO, TiO 2 and MgO nanoparticles in the virus elimination by means of three processes. 142

CONCLUSION
To sum up, metallic oxides nanoparticles including AgO, CuO, ZnO, TiO 2 and MgO and their uses as a surface disinfectant against Coronavirus were considered in this work.MgO nanoparticle samples were prepared through the heating method.The synthesized MgO nanoparticle showed that the average crystallite size was (18.55nm), lattice strain (0.0053), surface area (27.56m 2 /g) and d-spacing (2.1092).Magnesium oxide nanoparticle has properties that enable it to act, as a surface coating material against coronaviruses due to its unique properties beside it is eco-sustainable, cheap.Obviously, AgO, CuO, ZnO, TiO 2 and MgO nanoparticles will play a crucial part in the fight against COVID-19 by producing nanocoating materials that will inhibit the virus's infection and might be utilized to clean public spaces and medical devices.