Submit Manuscript | http://medcraveonline.com Abbreviations: EDS, energy dispersive X-ray spectroscopy; FT-IR, infrared spectroscopy or Fourier transform; DLS, dynamic light scattering; PCS, photon correlation spectroscopy Introduction At present a great interest has been visualized by the study of chemical species of nanometric size (Figure 1), this due to the applicability that has been demonstrated in chemical research areas due to its great variety of properties. Their scale of size and their metallic character makes them even more interesting in their practical application due to their biological, optical, catalytic properties, etc. 1 In the nanoparticles of metals, the optical properties focus on the mass oscillation of the free conduction electrons as a result of the interaction with the electromagnetic radiation, the electric field that is formed induces the formation of a dipole in the nanoparticle which is what attributes its restorative force due to the attempt to compensate for this effect, developing in parallel the study of properties and their multiple applications. 2 Silver has many uses, but undoubtedly one of the most interesting is its use as a disinfectant agent for antibacterial purposes. Due to the great boom that has existed in nanotechnology, different physical, chemical and biological methods have been developed for obtaining silver nanoparticles, so this paper seeks to describe some of the methods, their characterization and paying special attention to their capacity as an antibacterial agent. 3 Figure 1 Photos of silver nanoparticles in the image nanowires, nanocubes, nanopyramides, nanoprisms. 4 Chemical synthesis of silver nanoparticles The nanoparticles have been of great scientific value since they came to reduce the gap between the bulk materials and the atomic / molecular structures, the nanoparticles of silver are the most attractive due to the high surface area by volume ratio, the surface of the Nano particles are so important and should be controlled since a change in the size of the surface can generate a change in the physical and chemical properties of the nanoparticles. 4 But what does the properties of these nano particles depend on? What can we control so that the properties of them vary? When the particles reach a size between 1-100nm their properties are different at the electrical, chemical and physical levels, so it is evident that the properties are directly related to the size, so that by changing their size and shape, control is achieved of properties such as: temperature, redox potential, its color, conductivity, chemical stability, electrical qualities, optics, etc. 5 Extensive studies have shown that the size, morphology, stability and properties specifically of the nano silver particles are greatly influenced by the experimental conditions of their synthesis, the kinetics of the reaction, the interaction of the ions with the reducing agents and the absorption processes of the stabilizing agent used. 5 so that the specific control regarding its shape, size, distribution of the desired silver nano particle falls on the synthesis method that is selected. 6 Most chemical syntheses are based on the reduction reactions of metallic silver salts, but first you must select the shape of the nano particle that is sought, if it is spherical, if it is triangular, cubic, pyramidal, rods, cylinders, (Figure 2) once the form is known, then the method that best fits the nanoparticle shape is selected, since the speed of the reaction and the interaction with the stabilizers define the shape of the nano particle (Figure 3). It should be known, what happens in a nanoparticle synthesis process? As mentioned above requires a precise control in the synthesis to control the size and shape in order to obtain a set of particles with a certain property. In a synthesis by the general we have the following components which must be known to manipulate and work them: metallic precursor, reducing agent (solvent) and stabilizing agent (Figure 4). In addition, two very important formation processes are taken into account, one is nucleation, in which a high activation energy is required for the agglomeration of the atoms and the other is that of growth where, on the contrary, a low energy of Activation for ordering in the formation of particles, is in these points of the synthesis where the shape and size are totally dependent on the Int J Biosen Bioelectron. 2019;5(5):166‒173. 166 ©2019 Gamboa et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and build upon your work non-commercially. Synthesis and characterization of silver nanoparticles and their application as an antibacterial agent Volume 5 Issue 5 - 2019 Stephanie Marín Gamboa, 1 Ericka Rodríguez Rojas, 1 Verónica Vega Martínez, 1 José Vega- Baudrit 1,2 1 National University Heredia, Costa Rica 2 National Nanotechnology Laboratory, Costa Rica Correspondence: José Vega-Baudrit, Chemistry School, National University Heredia, Costa Rica, Email Received: September 15, 2019 | Published: October 22, 2019 Abstract A great interest for the study of nanoscale chemical species has been studied. This review presents the main methods of chemical reduction for the preparation of silver nanoparticles, such as the preparation of silver particles using NaBH 4 and ascorbic acid as a reducing and stabilizing agent, the preparation of silver particles using PVP as a reducing agent and the preparation of silver particles using DMF as a reducing agent. In addition, the main methods of characterization of silver nanoparticles are presented according to the size and morphology of the nanoparticles and the properties of surface and stability. Finally, the applicability of silver nanoparticles as an antibacterial agent is demonstrated. Keywords: silver nanoparticles, chemical reduction method, particle size, AFM, DLS, SEM, TEM, EDS, FTIR, antibacterial agent International Journal of Biosensors & Bioelectronics Research Article Open Access