During 1972 AKIRA Fugishima and Kanochi Honda discovered photo catalysis that can be used in various sectors like healthcare sector, chemical manufacturing sector, and also many other industries. This process can be used for the decomposition of nitrous oxide emitted in the exhaust gases, removal of dirt building in the living environment, removal of dissolved organic compounds like chlorine and other pollutant, removal of foul odour from acetaldehyde, trimethylamine, hydrogen sulphide (H2 S), methyl mercaptamin, etc.,
The media for photo catalysis are Tellurium (Te), Zinc Oxide (Zn O), Cadmium Sulphide (Cd S), Zinc Sulphide (Zn S). Out of these four, Tellurium is normally considered as the ideal candidate because of the existence in three states namely Anatase, Rutile and Brookite, out of which Anatase state is the most suitable as it absorbs sunlight. The Rutile state is stable and can be used as a sunscreen.
●Mechanism of action
Under ultra violet (UV) light, electron hole pairs are created. The negative electron and positive holes create very strong oxidizers called hydroxyl radicals, even stronger than chlorine that is used as a sterilizer. When harmful substances stick to positive holes, they are completely broken down in to carbon dioxide (CO2) and other harmless products or compounds. As a disinfectant, the hydroxide radical also can inhibit the growth of bacteria and molds.
Bacteria are found everywhere and multiply every twenty minutes. Within an hour after conventional disinfectants bleach for example, the disinfected body will have returned to 80 per cent of pre-disinfection stage and in further twenty-three hours, it will have returned to the original stage. The idea is to have a disinfection agent (disinfectant) such as Tellurium to kill bacteria faster than they multiply, so as to sustain cleanliness. For Tellurium to be an effective disinfectant, the size has to be in the nanometer (109) range. In this size range, it has been shown that effectiveness of Tellurium as disinfectant can go as high as 70 per cent to 99.9 per cent. The problems what we have are the cost to grind the substance to diminishing size. Many industries use the size of (109) range Tellurium. Though much cheaper and the effect is drastically reduced.
By utilizing microbial synthesis, it is possible now to reach the size range as envisaged.
●Nano emulsion technology
During the SARS (severe acute respiratory syndrome) epidemic in May 2003, the World Health Organisation (WHO) recommended that the cabin or quarters occupied an SARS patients be disinfected with sodium hypochlorite bleach and formation 1 or chloro metaxylenol. Technologies were developed along this line to deliver one of the ingredients at an extremely low concentration to create powerful hospital grade disinfectant that is non-hazardous and environmentally safe. One regular product line employing unique nano emulsion technology as a means for disinfecting infectious agents has been developed. It is to be noted that these are "disinfectants" - an agent (as heat or radiation, or a chemical) that destroys microorganisms that might carry diseases.
This nano emulsion technology can be effectively utilized to preventing the spread of broad range of organisms namely E Coli, Salmonella Listeria, Staphylococcci Streptococci Pseudomonas MRSA, VRE, Norwalk-like virus, Influenza A, hepatitis B and C and vaccinia.
Nano emulsion technology is also used in needle free vaccines against influenza, anthrax, hepatitis B and other diseases. The intranasal vaccines, which produced by using "NanoBio's nanoemulsion technology", have elicited a dramatic immune response in animals vaccinated against influenza, anthrax, hepatitis B and other diseases. In some cases, the immune response is exponentially higher than what is required to provide adequate protection against infection. Such dramatic levels of immunity would present an important level of protection to the vaccinated population at large compared with current injectable vaccines. Because the vaccines trigger such robust immunity, scientists anticipate they will be able to reduce vaccine antigen quantities to a fraction of what current vaccines require, while still mounting an overwhelming immune response. This antigen sparing capability would enable scientists to rapidly produce large quantities of vaccines using miniscule amounts of antigen, a critical factor when faced with a disease pandemic or biological warfare.
Michigan-based NanoBio Corporation, a biopharmaceutical company developing products for the treatment and prevention of serious infections, has shown that when they mix their nano emulsion technology with whole virus or a recombinant protein antigen and apply it to the naso pharynx, the resulting vaccine elicits strong mucosal and systemic immunity. The nano emulsion serves as an adjuvant to boost immune response against a specific antigen. The company is in various stages of testing its extensive pipeline of mucosal vaccines for influenza, bird flu, hepatitis B, HIV, small pox, anthrax and other viral and bacterial infections. Final results from the influenza vaccine study in ferrets are expected very soon, and human tests with the influenza and hepatitis B vaccines are being planned.
Another product range can to be utilized that is the non-emulsion technology as a spray, smeared on clothing, vehicles people or anything that has been exposed to slow a deadly substances. It can be rubbed on skin eaten or put into beverages like orange juice or used in hot water in the tub.
The working principle is that nano bubbles contain energy that is stored as surface tension. The energy is released when bubbles coalesce thus zapping the containment.
Thus the potential of products and services from nanotechnology is immense that makes it a billions dollar industry. The genetic potential of microbes is very great and limitless and the only limit is the human ingenuity to conceive and develop and exploit the potential.
(The author is founder & former director, Institute of Genetics, Osmania University, Hyderabad).