Synthesis of nanoparticles has been the subject of a lot of studies due to its commercial demands and wide applicability in various fields such as chemistry, physics, biology, material science, engineering, medicine etc. Silver nanoparticles can be synthesized by using number of methods such as chemical, physical, green methods etc. This paper reports the chemical synthesis of silver nanostructure. For synthesis silver nitrate solution is used as a metal precursor and sodium borohydride is used as a reducing agent. Four different sets of samples were synthesized by varying the amount of silver precursor. The formation of nanostructure was confirmed by presence of surface Plasmon resonance in absorption spectra. Electronic properties and optical band gap calculation was done by using absorption spectroscopy. Absorption spectroscopy showed that the maximum absorption was red shifted when the amount of silver precursor added was increased, indicating the increasing of size. Similarly, it was found that the optical band gap was decrease with increasing the amount of silver precursor. Moreover, the antimicrobial activity of synthesized silver nanoparticles was studied against both the gram positive as well as gram negative bacteria such as Staphylococcus aureus, E. coli and Pseudomonas respectively.