Nanotechnology Free Essays

Nanotechnology does not have to be as small as atoms or molecules, but it is much smaller than anything you can see with your naked eye. Many materials exhibit unusual and useful properties when their size is reduced. Researchers who try to understand the fundamentals of these size-dependent properties call their work nanoscience, while those focusing on how to effectively use the properties call their work nanoengineering. We will write a custom essay sample on Nanotechnology or any similar topic only for you Order Now Nanoscale Nanometer How do we measure the size of nanotechnology materials? We measure materials using the nanoscale. While not precisely defined, the nanoscale ranges from about 1 nanometer (nm) to 100 nanometers. From things the size of individual atoms on the smallest to what you might see with very good optical microscope at the largest size. A nanometer is one billionth of a meter. (A meter is about 10% longer than a yard. ) The prefix â€Å"nano† means â€Å"one billionth†, or 10-9, in the international system for units of weights and measure. A sheet of paper is about 100,000 nanometers thick; a single gold atom is about a third or a nanometer in diameter. Nanomaterials By nanomaterials is a term that refers to all nanosized materials. When particles are purposefully manufactured with nanoscale dimensions, we call them engineered nanoparticles. There are two other ways nanoparticles are formed. Nanoparticles can occur as a byproduct of combustion, industrial manufacturing, and other human activities; these are known as incidental nanoparticles. Natural processes, such as sea spray and erosion, can also create nanoparticles. Many important functions of living organisms take place at the nanoscale. The human body uses natural nanoscale materials, such as proteins and other molecules, to control the body’s many systems and processes. A typical protein such as hemoglobin, which carries oxygen through the bloodstream, is 5 nms in diameter. Nanoparticles, Nanotubes, Nanofilms Think of these simply as particles, tubes, and films that have one or more nanosized dimension. Nanoparticles are bits of a material in which all three dimensions of the particle are within the nanoscale. Nanotubes have a diameter that’s nanosize, but can be several hundred nanometers (nm) long or even longer. Nanofilms or nanoplates have a thickness that’s nanosize, but their other two dimensions can be quite large. How to cite Nanotechnology, Essay examples Nanotechnology Free Essays Nanotechnology is a new multidisciplinary science interfering with many research areas and aspects. This technology deals with so small particles ranges from 1 to 100 nm (Birla et al., 2009; Husseiny et al. We will write a custom essay sample on Nanotechnology or any similar topic only for you Order Now , 2015). Nanoparticles of some metals like Au, Ag, Pt and Cu have paid more attention because of their biotechnological benefits (Rai and Duran, 2011). Research revealed the multiapplication of nanoparticle due to their unique properties in electronics, medicine, agriculture, pharmaceutic and environment (Nanda and Majeed, 2014; Dasgupta et al., 2015). Metal nanoparticles emerged as an alternative variety of antibacterial agents against strains of high resistance to the classical antibiotics (Naseem and Farrukh, 2015). Nanoparticles were used as antiviral agents (Gaikwad et al., 2013), effective antibacterial (Singh et al., 2013), cancer cells and antitumor (Daenen et al., 2014). Many researches have been directed to apply the nanoparticles of metals as anthelmintic (Garga and Chandrab, 2012), antifungal (Kim et al., 2012), antiprotozoal (Said et al., 2012), , acaricidal (Marimuthu et al., 2013) and larvicidal (Muthukumaran et al., 2015). Nanoparticles have many chemical and physical characteristics that differ from the metallic particles. Specific characteristics of nanoparticles such as their optical, physicochemical, mechanical properties make them crucial in many applications. Therefore, nanoparticles could be the key factor for the future technologies. Scientific as well as public associations are paying their attention for nanoparticles technology as a good investment source. Nanoparticles could be produced via physical, chemical or biological methods (Haider and Kang, 2015; Ebrahiminezhad et al., 2017). Both chemical and physical methods use reducing agents such as sodium borohydride, sodium citrate and alcohols (Rai and Duran, 2011). However, using of microorganisms in synthesis of nanoparticles represents another great achievement because of the economic and ease production (Shelar and Chavan, 2014; Patel et al., 2015). Research revealed that biological methods is an inexpensive and eco-friendly way for synthesis of nanoparticles. This method used biological agents including bacteria, fungi, yeast and plants (Mourato et al., 2011). Recently, emerging such microorganisms as eco-friendly nano-factories to manufacture inorganic nanoparticles was attractive (Lee et al., 2004; Lengke et al., 2007). Fungi were mentioned as excellent candidates for metal nanoparticle synthesis because they contain many of enzymes that induce the production (Sastry et al., 2003). It was assumed that the mechanism involved in nanoparticles production by fungi was due to cell wall sugars that could reduce the metal ions (Mukherjee et al., 2002) and because they have the high cell wall binding capacity, metal uptake and secrete more amounts of proteins lead to the higher productivity of nanoparticles (Vahabi et al., 2011). Fungi have some advantages over the other microorganisms regarding the synthesis of NPs, because fungal mycelia are able to resist pressure, high temperature and easy storage in the laboratory (Kiran et al., 2016). There are many of metals for biosynthesis (NPs) such as copper, zinc, iron, iron trichloride, lead carbonate, gold and silver (Siddiqi and Husen, 2016). In addition, silver NPs could be synthesized by fungi either intracellularly or extracellularly but the extracellular biosynthesis downstream process much easier and showed more activities against many pathogens (Ahmad et al., 2003). Among the active fungi that were reported to produce nanoparticles; Rhizopous oryzae produced nanoparticles intracellularly of gold (Das et al., 2012), Verticillium sp extracellularly peodcued gold and silver nanoparticles (Soni and Prakash, 2014) in the size range of 20–51 nm. However, F. oxysporum produced nanoparticles of silver of 5–15 nm and 8-14 nm in diameter extracellularly (Ahmad et al., 2003; Senapati et al., 2005). Many other fungi were approved for their productivity of nanoparticles of different metals either extracellularly or intracellularly including: Phoma sp. (Chen et al., 2003), the endophytic fungus Colletotrichum sp. (Shankar et al., 2003), Aspergillus fumigatus (Kuber and D’Souza, 2006) , Fusarium acuminatum (Ingle et al., 2008) , Trichoderma asperellum (Mukherjee et al., 2008), F. semitectum (Sawle et al., 2008), Phoma glomerate (Birla et al. 2009), F. solani (Ingle et al., 2009) , plant pathogenic fungi Aspergillus niger (Gade et al., 2008; Jaidev and Narasimha, 2010), Aspergillus flavus (Vigneshwaran et al., 2007; Jain et al., 2011) , Paecilomyces lilacinus (Devi and Joshi, 2012), endophytic fungus Pencillium sp. (Singh et al., 2013), Aspergillus foetidus (Roy and Das, 2014), Rhizopus stolonifer (AbdelRahim et al., 2017), Penicillium Oxalicum (Bhattacharjee et al., 2017) and Trichoderma atroviride (Saravanakumar and Wang, 2018). Many recent reports have shown that production of nanoparticles by fungi are could be affected by various condition of temperature, biomass weight, time and pH ( Balakumaran et al., 2016; Liang et al., 2017; Othman et al., 2017). Husseiny et al. (2015) reported that most important factors that were affecting the biosynthesis of AgNPs were the temperature, pH, time, the concentration of AgNO3 and amount biomass. Narayanan and Sakthivel (2010) approved that incubation at 27 0C for 72 h with 7 pH and 10 g of the fungal biomass and 1mM concentration of AgNPs were considered the optimum conditions for production of AgNPs from AgNO3 by fungi. Researches showed some variations in the characteristics of the biosynthesized AgNPs by different fungal species. These variations could be due to the source of fungal isolates or strains and types of medium (Devi and Joshi, 2012; Roy and Das, 2014). When Alam et al. (2017) compared the different types of media, they found Czapex dox broth was a good medium to produce enough mycelial biomass to synthesize AgNPs. This because this medium contains essential carbon and nitrogen source along with other vital macro and micronutrients such as magnesium, sodium, calcium, potassium, iron and zinc which are vital for fungal growth.Nowadays, application of AgNPs confirmed their effectiveness in treatment of cancer, bone implant, anti-inflammatory and their biocidal activity against many bacteria and pathogens (Husseiny et al., 2015; Majeed et al., 2016). The antibacterial properties of AgNPs are due to the oxidation and liberation of Ag+ ions into the environment that makes it an ideal biocidal agent (Sivakumar et al., 2015). It is expected that the large surface area to volume ratio as well as high fraction of the surface atoms of the nanoparticles increase their antimicrobial activity as compared with bulk silver metal (Joy and Johnson, 2015). Moreover, the small size of the nanoparticles facilitates their penetration inside the cell. Additionally, excellent antibacterial properties exhibited by AgNPs are due to their well-developed surface which provides maximum contact with the environment (Mitiku and Yilma, 2017). Recent research approved the antibacterial activity of the silver nanoparticles against many bacteria especially those having the capability to cause severe disease for the human such as Salmonella enterica, Enterococcus faecalis, Streptococcus, Proteus mirabilis, Staphylococcus aureus, Escherichia coli, Staphylococci and Pseudomonas sp (Devi and Joshi, 2012; Shelar and Chavan, 2014; Muhsin and Hachim, 2016; Madakka et al., 2018; Saravanakumar and Wang, 2018). However, shape, dimension, and the exterior charge as well as the concentration of the AgNPs are important factors that affect the antimicrobial activity the nanoparticles against the tested bacteria (Madakka et al., 2018). Devi and Joshi (2012) approved the antibacterial activity of AgNPs comparing with erythromycin, methicillin, chloramphenicol and ciprofloxacin agents Staphylococcus aureus, Streptococcus pyogenes, Salmonella enterica and Enterococcus faecalis. They showed that the diameter of inhibition zones obtained by the silver-nanoparticles, with 5-50 nm in diameter, were more than those obtained by the antibiotics. Shelar and Chavan, (2014) showed that Bacillus subtilis and Staphylococcus sp were inhibited by silver nanoparticles with diameter of 17-32 nm in very close pattern to the standard antibiotic streptomycin. Muhsin and Hachim (2016) reported the best concentration of silver nanoparticles with diameter 8-90 nm that showed strong antibacterial activity against Escherichia coli, Proteus mirabilis, Pseudomonas aeruginosa, Salmonella typhi and Staphylococcus aureus streptomycin was 100  µl/ ml. Based on the above-mentioned information, we assume that fungi as bio-factories for the biogenic synthesis of the silver nanoparticles are very interesting during eco-friendly and safe technology, also for future application as antimicrobial agents. How to cite Nanotechnology, Papers