Silver has been used since Roman times as a disinfectant because of its well-known antimicrobial properties. AgNPs are considered attractive building blocks for nanomaterial architectures based upon the nanoparticles size and shape (Shipway etal 2000). The antibacterial activities of silver and silver nanoparticles are having various important applications in biomedical field especially in topical ointments to prevent open wound and burns infection.(Duran etal 2005).The antibacterial properties of silve rnanoparticles are also extensively used for wound dressings for diabetic wounds and traumatic injuries and also to prevent bacterial colonization in prostheses and to reduce infections in surgically implanted catheters. AgNPs are also used
Due to research such as this, the nurse believed that an Aquacel dressing would assist in fighting the patient’s infection and aid in overall wound healing. This was confirmed by the attending primary care physician, who affirmed the usage of the silver based dressing.
The association of metal nanoparticles and antibiotics is a very promising area of research. Silver nanoparticles are interesting when compared with silver ions due to their larger size, in turn, improves the capacity to react with several molecules. The bactericidal action of silver nanoparticles and amoxicillin was investigated using E. coli and silver nanoparticles of 20 nm in size (prepared by reducing an aqueous solution of AgNO3 with a freshly prepared aqueous ascorbic acid solution and ammonia). Microbiological tests
In the medical industry there is high demand for antibacterial and antiseptic products, especially in hospitals and other medical institutes. Antibacterial products fall into two categories, residue producing, that provide a long lasting antibacterial action like triclosan, and non-residue producing which are generally fast acting and can rapidly kill bacteria and disappear quickly leaving no residues, like alcohols. (APUA, 2014) But these are costly, time absorbing and inefficient to produce. (how products are made, 2016) There is also the very real threat of superbugs.(antibacterial resistant microbes) Silver Nanoparticles could produce a quick and cheap antimicrobial that conserves resources.
Nanotechnology has expanded human capabilities to perform tasks by manufacturing nanostructured materials with certain properties, properties which we use in many different areas. In the Medical industry, nano-gold particles are being manipulated to have bacterial detecting properties. Nanotechnology simply is “ The branch of technology that deals with dimensions and tolerances of less than 100 nanometres, especially the manipulation of individual atoms and molecules.” This technology is specifically useful in the medical industry where the shape and size of specific nanoparticles led directly to the problem, for example cancer cells or specific bacteria cells. But, the size of the particles impact the properties of the particles.
Today many common commercial products contain some sort of engineered nanoparticles. “Examples include cosmetics, sunscreens, clothes, solar cells, sporting good[s], paints, and electronics” (Kosal 8). Although major developments have only occurred in the last decade, the US military began conducting nanotechnology research in the early 1980s. It was not until the mid-1990s, after the Department of Defense (DoD) identified nanotechnology as one of the six ‘Strategic Research Areas’ of Interest, that major investments in the research and development in nanotechnology began. Nanotechnology research seeks to advance both offensive and defensive military objectives (Lele 234). In January of 2000, President Bill Clinton “unveiled the National Nanotechnology Initiative (NNI) where he called for an initiative with funding levels around 500 million dollars” (Tate 23). “All branches of the U.S. military currently conduct nanotechnology research, including the Defense Advanced Research Projects Agency (DARPA), Office of Naval Research (ONR), Army Research Office (ARO), and Air Force Office of Scientific Research (AFOSR)” (Tate 20). By the conclusion of this paper, the reader will have a basic understanding of nanotechnology and its applicability in military affairs. Additionally, the reader will understand the hazards of nanotechnology in order to determine if the military should continue to focus on nanotechnology.
After completing my doctoral degree at the University of Louisville, I turned my focus to the surface chemistry of nanomaterials for preparing bioconjugates, a continuation of my work on surface chemistry on nanomaterials. In another work during the postdoctoral research period, I was able to publish a work on dielectrophoresis manipulation of metal nanoparticles to increase substantially the amount of frequency of collisions (by the factor of 101-103) of the metal nanoparticles with the surface of
Chemical synthesized nanoparticles raises certain toxicity issues that lead to development of eco-friendly methods to synthesize silver nanoparticles. Green synthesis of silver nanoparticles using plant extract is eco-friendly nanoparticle synthesis approaches (13). This is one step reaction as reducing and stabilization agents both are present in the plant extract. Silver nitrate and extract when mixed together forms light yellow coloured solution in starting that turns into dark brown solution later. The appearance of a dark-brown color in solution containing the extract and silver nitrate was a clear indication of the formation of AgNPs in the reaction mixture. Nanoparticle shape and size as observed by TEM reveled that these particles are not perfectly spherical but also have quasi-spherical, triangular and pentagonal shapes. Heterogeneous particles formation occurs due to rapid utilization of the capping molecules. Particles formed later are with less capping molecules and becomes thermodynamically unstable. These particles with less number of capping molecules then tends to minimize high surface energy and gets shape of a triangle or pentagonal having smooth angles (14, 15). XRD analysis and peak matching with similar AgNPs confirmed the crystalline structure of AgNPs. Two extra peaks present in the XRD spectra marked by star indicate the presence of biological moieties in the AgNPs (14). Hence, biological functional group involvement in
Abstract: In this study, we report a convenient, simple, economically viable and eco-friendly method for the synthesis of gold nanoparticles (AuNPs) with carboxymethyl gum kodagogu (CMGK). Carboxymethyl gum kondagogu is a nontoxic and renewable. It is used as reducing, stabilizing and capping agent for the synthesis of AuNPs without using any chemical reducing agent. The effect of various parameters such as concentration of HAuCl4 and CMKG and reaction time for the synthesis of AuNPs was studying. The green synthesized AuNPs were characterized by UV−vis spectroscopy, Fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM) and X-ray diffraction techniques. The resultant CMGK capped AuNPs are extremely stable and had significant antibacterial action on both Bacillus subtilis (B.subtilis) and Escherichia coli (E. coli). The catalytic activity of the CMGK capped AuNPs was studied the reduction of 4-nitrophenol (4-NP) to 4 Amino phenol (4-AP) in the presence of NaBH4. With respect to the 4-NP the kinetics of the reaction were found to be a pseudo-first-order.
Fig. 1a shows the UV–vis absorption spectrum of the as-prepared Ag@C-nanowires suspended in deionized water, exhibiting a main peak at 386 nm and a shoulder peak at 360 nm, corresponding to the optical finger print of silver nanowires. The absorption peak at 360 nm is attributed to the longitudinal plasmon mode of silver nanowires and is similar to that of the bulk silver, and the absorption peak at 386 nm is attributed to the transverse plasmon mode of silver nanowires. These two absorption peaks suggest that pure Ag@C-nanowires were successfully synthesized, and the Ag@C-nanowires had a sheath thickness of ~10 nm, consistent with our electron microscopic studies shown in Fig. 2c. Fig. 1b shows the typical X-ray diffraction (XRD) pattern
Increased worldwide use of nanomaterials in almost every field promotes the design and production of various kinds of nanoparticles and they are being used across all fields of science, such as chemistry, physics, materials science, molecular biology, reproduction, biotechnology and engineering (Zhao et al., 2012; Rafeeqi and Kaul, 2010a,b). Nanoparticles have a greater surface area by volume ratio than larger particles thus exerting a stronger effect on the surrounding environment and reacting more with other substances. These factors affect their chemical reactivity, membrane permeability and also their mechanical, optical, electrical and magnetic properties. Increasing use of nanoparticles has also attracted human attention to
In addition to injectable applications, nanometals are also synthesized for medical stent drug delivery. This type of drug delivery vehicle involves the permanent fixture of a nanoparticle apparatus that releases therapeutics in vivo over time. Nanometal stents are fundamentally green as they are constructed to biodegrade in vivo and excreted through the renal system as they degrade. The original construction of nanometal stents involved iron; however, iron stents have caused inflammation in vivo.
Systematic studies on the structural change of silver nanoparticles, which are easy to change shape and exhibit excellent localized surface plasmon resonance effect, were carried out and the predicted shape change was compared to the actual nanoparticles. Herein, key information on the alteration of silver nanoparticles was determined theoretically by a computational method, discrete dipole approximation (DDA). The galvanic reaction and sulfidation reaction were suggested to improve the stability of silver nanoprism (AgNP). In addition, the effect of additionally generated spherical particles, silver nanosphere (AgNS), on the absorbance was studied. Both AgNP and AgNS formed hollow nanostructure after the galvanic reaction, and these
In recent times, infectious diseases continue to pose a major healthcare issue in developing countries making it imperative to develop logical solutions for robust and rapid diagnosis and treatment of these infections. Traditional techniques suffer from limitations, including laborious specimen processing, bulky instrumentation, and slow result readout. In view of the urgency for sensitive, specific, robust and rapid diagnostics, numerous advancements have been made in the area of nanotechnology to aid this effort. This methodical analysis will focus on the recent developments in nanotechnology-based diagnostics of bacterial pathogens in developing countries. The aim of this review article is to describe the
Silver nanoparticles were biosynthesized via a green route using 10 different plants extracts and formed AgNPs were tested against drug resistant microbes and their biofilms. These nanoparticles were characterized using UV- vis spectroscopy and TEM which confirmed their synthesis, shape and size. FTIR clearly demonstrated the presence of the bio-groups on the surface of AgNPs. XRD confirmed the crystalline structure of AgNPs. TEM images were further analyzed using Image J software which showed that majority of particles were under 100 nm and majorly distributed over 1 to 60 nm size range. Their antimicrobial efficacy was checked against bacteria harboring antibiotic resistance genes like CTX-M-3, CTX-M-15, OXA-1, arm A, SHV-1 and NDM-1 in gram negative bacteria and fluconazole, amphotericin B and itraconazole resistant genes in fungus. Gram positive bacteria and fungi Candida albicans were inhibited at higher MICs values in comparison to Gran negative bacterial strains. The result indicated that these particles were antibacterial in nature without
Silver is known to be very efficient material since ancient times for its microbicidal properties to treat diseases, such as, ulcer, chronic wounds, sepsis, acute epididymitis, tonsillitis, and infections and to prevent the eye diseases in infants.1,2 But with the passage of time use of Ag is reduced due to development of new antibiotics.3 However, an introduction of nanotechnology, nanoparticles during the last decade have proved that this element can be used in almost every field of application due to their tremendous behavior with reduction in size (high surface to volume ratio).