BIO SMART AND SAFE BUS
NANOSILVER COATING TO REDUCE THE SPREAD OF BACTERIA AND VIRUSES ON THE BUS
DR. Agus Subagio
The spread of the Covid-19 virus is currently a major problem globally. The number of cases due to the Covid-19 virus is increasing day by day, and one of the causes of the most spread of this infection is through public transportation (Zhenget al., 2020). This certainly has serious consequences for every country, including Indonesia. Various efforts have been made by the government to accelerate the handling of pandemics through various things. One of them is with large-scale social restrictions. People are urged not to do crowd-in-crowd activities and to comply with all health protocols. But not a few people who ignore the appeal. They do their usual activities and do not care about the direction of the government.
Government efforts in preventing pandemic spread certainly cause various problems in various fields such as tourism, transportation, education and others. Therefore, continuous improvement is carried out as currently developed in the field of transportation is the application of the concept of ‘BIOSMART AND SAFE BUS’ designed to inhibit the spread of viruses. This concept is an application of health protocols to prevent the spread of Covid-19 specifically created for bus transportation, based on the understanding of ‘disease triangles’ and ‘healthy triangles’. The concept of ‘triangle disease’ states that the appearance of a sick condition, caused by reciprocal interactions between the ‘host’ (e.g. bus passenger), ‘agent’ (cause, e.g. virus) and ‘environment’ (e.g. bus cabin), in a state of balance (homeostasis). The concept of a ‘healthy triangle’ shows that to stay healthy, individuals (passengers) must have balance in aspects of physical health, mental health and social health. Therefore, the concept (understanding) ‘BIOSMART AND SAFE BUS’ is to apply the understanding that the bus and cabin environment in the bus is a healthy biological environment because the engineering of the bus cabin is ‘smart’ (intelligent) in terms of ‘physical distancing’ (arrangement of passenger seats), regulation and filtering of air circulation as well as nanosilver application on the entire surface of the bus cabin to reduce the number and germ density (including viruses) in the bus cabin. Bus ‘BIOSMART’ means the bus that is carried out environmental balance control and germs / viruses in the bus cabin and carried out deactivation and filtering of viruses, so that the amount and density (viral load) is as small as possible or within safe limits. The notion of a ‘SAFE’ bus means that passengers in the cabin are also required to wear masks, making it safe from the possibility of exposure to germs or contracting from other passengers.
A potential breakthrough is also to create a surface layer with relatively low surface energy values that can expel glycoprotein spikes from the surface. An anti-microbial coating solution has been developed for all surfaces with an effective nano-active combination, with the support of literature that is proven to be anti-viral as well. Literature studies show that nanoparticles (NP) of various metals and metal oxides such as Zinc Oxide nanoparticles (ZnONPs), Cuprous Oxide nanoparticles (CuONPs), Silver or Silver Nanoparticles (AgNPs), Nanosized Copper (I) Iodide Particles (CuINPs), gold nanoparticles in Silica Nanoparticles (Au-SiO2NPs) and also some quartile ammonium cations commonly called QUATs are very promising to disable viruses and are well proven.
Silver Nanoparticles (AgNP) have reportedly inhibited viral nucleotide replication, its main mechanism being virulent. It binds to electron donor groups such as Sulfur, Oxygen, and Nitrogen commonly found in enzymes in microbes. This causes the enzyme to be denatured so that it effectively paralyzes the energy sources of cells and microbes will quickly die; Cationic silver (Ag+) or QUATs work to disable SARS-CoV-2 by interacting with its surface (spike) of S protein based on its content such as working on HIV, Hepatitis virus, etc. Since the omniphobic NANOVA HYGIENE+TM antimicrobial coating has been able to disable various pathogenic bacteria and further based on the available scientific support, then the current formula can work against a wide spectrum of viruses as well.
Initial anti-viral tests of NANOVA HYGIENE+TM have been conducted using MS2 Bacteriophage (Poliovirus), a small RNA virus that is not covered by the Leviviridae family. The results showed with 99.9% anti-viral efficacy in just 2 hours of contact with the surface according to AATCC 100-2012 global standards. Furthermore, anti-virus tests have established the ability on COVID-19 inactivation on different surfaces to stop the secondary spread from various surfaces to living cells by touch. Once validated, AgNP has many applications for almost all surfaces such as fabrics (masks, gloves, doctor’s coats, curtains, bed linen), metal (elevators, door handles, nobs, fences, public transport), wood (furniture, floors, and partition panels), concrete (hospitals, clinics and isolation wards), plastics (switches, kitchens and household appliances) and potentially saving many lives.
Especially in the application of nanosilvers on buses, the entire interior of the bus is coated with nanosilvers. Analysis that occurred on the surface has been done for 1 month by conducting swab tests assuming to see how much bacteria or viruses can survive sticking to the interior of the bus. Figure 1 shows SEM tests of nanosilver materials overlaid in silicon wafers.
Figure 1. SEM images of nanosilver material are overlaid on the surface of the silicon wafer. (Subagio A., 2009)
In the process of application of nano silver coating in transportation mode in this case is a bus vehicle can be done through 2 techniques namely spray and swab techniques. Differences in techniques are more likely to be on the size and type of fields to becoating. Spray technique is more suitable to be applied to surface areas that are wide and easy to reach sprayer tools such as bus walls, chairs, floors, inner roof. While the swab technique is more suitable to be applied to the surface area that is small, round and close to electrical equipment that needs attention such as on the dashboard, steering wheel, passenger handle, door handles.
The main materials used in the coating process here are nanosilvers and water. The nanosilver used has been modified with a water-soluble, inexpensive and safe polymer that serves to bind the nano silver on the surface of the coated object, so that the nanosilver is not easily detached from the surface despite friction and water. It is useful to maintain nanosilver can last a long time and effective in killing bacteria or viruses without the need to apply it often repeatedly because nano silver works in contact. So that if bacteria or viruses attach to the surface of objects that arecoating nanosilver will be able to be directly inactivated.
This nanosilver coating innovation was included in a collaborative research between Diponegoro University, Karoseri Laksana Company, PO. Sumber Alam (bus company) and supported by KNKT (National Transportation Safety Committee).