Professor Palli Thordarson of the School of Chemistry at the University of New South Wales, Sydney explains to us why soap is more effective than alcohol and other detergents in destroying the structure of viruses.
Why is soap effective for the new coronavirus and even for most viruses? Because it's a self-assembled nanoparticle, in which the loosest connection is the double lipid layer.
It sounds too scientific, let me explain.
Soap breaks down the fat membrane, and the virus falls off like a house made of cardboard and "dies", or rather becomes inactivated as the viruses no longer live. Viruses are able to work outside the body for hours, even days.
Detergents, in liquid form, wet towels, gels or creams that contain alcohol (and soap) have a similar effect but are not as good as regular soap. The antimicrobial agents in these products are not very effective with the virus structure. As a result, many antibacterial products are basically just an expensive version of soap in the way they affect viruses. Soap is best, but wet towels with alcohol are also good when using soap that is inconvenient or not portable, for example in office reception areas.
Super molecular chemistry
But why is soap good? To explain this, I'll take you on a journey of super molecular chemistry, nanoscience and virology. Although I am only an expert on super molecular chemistry and related to nanoscience and not a virologist, I have always been attracted to viruses. Because I see them as one of the most interesting examples of how both super-molecular chemistry and nanoscience converge in viruses in different ways.
Most viruses consist of three main blocks: RNA, proteins and lipids. The RNA and genetic material of the virus - it is similar to human DNA. Proteins play many roles, including breaking down the surface to invade the target cell, enabling the virus to replicate and essentially become an important building block-like component in the virus structure.
The lipids then form a mantle outside the virus, both for protecting and supporting the spread of the virus as well as invading human cells. The trio of RNA, proteins and lipids collect themselves to form viruses. More serious, "covalent" bonds are not strong enough to keep these components together. Thus, virus self-assembly is based on weak "non-covalent" interactions between proteins, RNA and lipids. Together, these activities are similar to Velcro's patches, so it is difficult to break up this self-assembled virus particle. We can still do that with soap though!
Most viruses, including the coronavirus, are about 50 to 200 nanometers in size - so they are actually nanoparticles. Nanoparticles all have complex interactions with the surfaces on which they are located; this is similar to the virus. In fact, leather, steel, wood, fabric, paint and porcelain all have very different surfaces.
Soap is more effective in the interaction between the virus and the skin surface, and so the virus is washed away like a paper house.
When a virus invades a cell, RNA "robs" the cell like a computer virus and forces the cell to make new copies of the virus' RNA and other proteins that make up the virus. New molecules of RNA and new self-assembly proteins with lipids (available in cells) to form new copies of viruses. The virus does not copy itself, it creates copies of the basic components to form new viruses.
All new viruses eventually flood the invaded cell, resulting in dead or exposed cells, releasing the virus to spread throughout other cells. In the lungs, the virus invades the airways and mucous membranes. When he coughs or sneezes, tiny droplets of air can travel more than 9 meters. For coronavirus carriers, the droplet can travel more than 2 meters, so be careful!
The skin is the ideal surface for viruses
The droplets will land on surfaces and dry quickly, but the virus will remain active. What happens next is in the aspect of super molecular chemistry and how self-assembling nanoparticles (like viruses) interact with their environment. Wood, fabric and leather interact very strongly with viruses because the same molecules interact more strongly.
On the other hand, the problem here is also the surface structure. The virus will stick on the flatter surface and push away on the rough one. Why? The virus is made up of basic components with water-like hydrogen bonds and hydrophilic interactions. For example, the surface of fibers or wood can form on many hydrogen bonds with viruses. Contrast, steel, ceramics do not form much hydrogen bonds with the virus, so the virus indifferent to those surfaces.
So how long can the virus work? It also depends on a number of other issues. The new coronavirus is thought to remain active on preferred surfaces for hours, possibly all day. So, what makes the virus less sustainable? Moisture (decay), sunlight (UV rays) and heat (molecular motion).
The skin is an ideal surface for a virus. It is organic, and the proteins and fatty acids in surface cells interact with the virus through hydrogen bonds and hydrophilic interactions "such as fats." So, when he touched the steel surface with a virus particle attached to it, it would grab his skin and transport it to his hand. But he was not infected immediately; If he touched his face, then the virus was successfully transported. If the virus is still in your hand, you can pass it on to another person via handshake.
And now viruses are a danger to the respiratory system and mucous membranes in and around the eyes and nose. So, the virus can invade and he is infected, unless his immune system kills the virus. So, you often touch your face often? Most people usually touch their face once every two to five minutes. So, you are at high risk of getting the virus on your hands unless you wash your hands carefully.
So, try to wash your hands with clean water. However, only water is not enough to overcome strong interactions such as glue between the skin and the virus through hydrogen bonds. The virus is still on and not leaving your hands.
Soap breaks down virus structure
Soap water is completely different from normal water. Soap contains substances such as fats which are still called amphiphile, structurally similar to the lipids in the virus membrane. Soap molecules "compete" with lipids in the virus membrane. That's how soap removes common dirt from the skin.
Soap molecules compete with a lot of non-covalent bonds, which bind proteins, RNA and lipids together. In addition to water, soap effectively decomposes this adhesive.
Soap also defeats interactions between viruses and skin surface. Immediately after the virus falls, depending on the combination of water and soap. And until the virus is washed away!
Looking closely, the skin is rough and wrinkled, which is why you need to get enough soap to make sure the soap can reach every corner of your skin to eliminate any virus.
Alcohol-based products are also among the "cleansing" and "antibacterial" products due to their high alcohol, typically about 60% to 80% ethanol, with occasional addition of isopropyl alcohol, water and a little soap.
Ethanol and other forms of alcohol not only quickly form hydrogen bonds with virus materials but also more fat than water. From here on, alcohol degrades the lipid membrane and disrupts other macromolecular interactions in the virus.
Anyway, you needed a higher amount of alcohol (maybe over 60%) to decompose the virus. Vodka or whiskey (usually containing 40% ethanol) cannot eliminate the virus quickly. Overall, alcohol or alcohol is not as effective as soap in this task.
So, super molecular chemistry and nanoscience tell us not only about how the components of the virus assemble themselves, but also how we can defeat them with something as simple as soap.
Source: Light Ray