Nanometer

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          Nanotechnology is an emerging technology that deals with sub-microscopic dimensions. Nanotechnology is a technology that is linked to features of nanometer scale. The technology constitutes thin films, fine particles, chemical synthesis, advanced microlithography, and so on. Nanotechnology thus defines the spectrum of activities at the level of atoms and molecules with amazing applications in the real world.

Although the research is ongoing for 15 years but the development of the scanning probe microscope (SPM), discovery and potential of fullerenes and a related structure, the nanotube has generated the current interest in the field. Fullerenes and Nanotubes are the compounds made up of carbon atoms. The fullerene molecule is composed of 60 carbon atoms (C60). A vast research is going on fullerene molecules to test for their use as potential drug delivery system for cancer, AIDS and other diseases.

The latest study in nanotechnology deals with metal nanoparticles and their interaction with HIV-1, thus a step to treat AIDS. It was found that silver nanoparticles of sizes 1-10nm when attached to HIV-1, prevented the virus from bonding to host cells. This research was published in the Journal of Nanotechnology, was a joint project between the University of Texas, Austin and Mexico University, Nuevo Leon.

Nano granules has average diameter that is nearly same as that of virus or ever smaller and it is this small size that impacts the virus. The nano particles generate a suspending isolation effect once they enter the body. This effect can potentially block out the replication of virus. These particles have a great surface adsorption effect owing to their high surface area. This surface area makes virus, metabolic product and virus duplicating parts adsorbed and ended. When the nano granules enter the body they rub with the rotating cells thus causing nano rubbing mechanical effect. This can stop virus from affixing to the surface of cells and sheds off virus adhering to the cell, hence opposing its transcription

            In the latest experiments, scientists mixed silver nanoparticles with three different capping agents. Capping agents are the agents which if not used result in production of big crystals rather than nanocrystals. The capping agents used are: foamy carbon, poly (PVP), and bovine serum albumin (BSA).

Transmission electron microscopy (TEM) demonstrated that the silver nanoparticles in the foamy carbon matrix were coupled and after that, an ultrasonic bath in deionized water freed a large number of nanoparticles. These nanoparticles were of size 16.19 (+-8.69)nm and had a vast variety of shapes, such as icosahedral, decahedral, and elongated.
            As explained by the scientist Yacaman, in the synthesis procedure, the foamy carbon-coated nanoparticles are more possibly to have broad shape distribution. Scientists used the electron beam to free the residue of the nanoparticles from the joined bundle.

While using the capping agent, PVP-coated silver nanoparticles, scientists used glycerine as a dissolving agent. These particles were of size 6.53 (+-2.41).

In the third preparation, scientists used serum albumin, the most common protein in blood plasma. The sulfur, oxygen, and nitrogen chemicals in BSA stabilized the nanoparticles, which were in the range of 3.12 (+-2.00) nm.
            These absorption spectra of the different preparations were studied to analyze their shapes . Yacaman studied that  spherical nanoparticles were absorbed in the blue region of the spectrum. Also, the UV-Visible spectra graphs helped in determining the size of the nanoparticles. It was found that the surface plasmon resonance peak wavelength increased with size.

            After this  each of three silver nanoparticle-preparations in HIV-1 cells were tested. Then Yacaman and his colleques incubated the samples at 37 C.
The study found that a silver nanoparticle concentration greater than 25 ug/mL worked more effectively at inhibiting HIV-1 cells. Added to this, the foamy carbon was a slightly better capping agent because of its free surface area. In these studies, size also played a role since none of the attached nanoparticles were greater than 10nm.

           Scientists think the nanoparticles bonded through the gp120 lipoprotein knobs on HIV-1, using the sulfur residues on the knobs. The spacing between the knobs of ~22nm matched the center-to-center nanoparticle spacing.
Though the study shows that silver nanoparticles can be used to treat HIV-1, some more research is needed in this field to further check the effects. Moreover, the longevity of these metal nanoparticles is still a question mark and needs an extensive research. Such tests will be done on humans to see the proper effects.

Yacaman and his associates confirmed the highly positive effects of  silver nanoparticles against various kinds of viruses. Certain Methicillin resistant staphylococcus aureus are also to be tested.Yacaman also researched the silver nanoparticles to be effective against many other micro-organisms.

Nanotechnology is also used in testing techniques to test various diseases. Nanometre-sized quantum dots can be made to tag biological molecules for the recognition of proteins that point out disease status. However, this technique doesn’t have those shortcomings, which are attached with regular organic dyes used to mark cells. Quantum dots could ultimately be used in clinical analytic tests to rapidly spot molecules linked with cancer cells and HIV/AIDS. This has the greatest advantage to developing countries, where over 95% of new HIV infections occurred in last few years. Quantum dot optical biosensors can also help in the detection of TB10, which along with HIV and Malaria is accountable for 50% infectious disease mortality in developing countries.