Silver nanoparticles-A review

Silver is a soft, white, lustrous transition metal possessing high electrical and thermal conductivity. It is used in many forms as coins, vessels, solutions, foils, sutures, and colloids as lotions, ointments, and so forth. Silver nanoparticle has various advantages such as longer shelf-stability, high carrier capacity, longer clearance time, increase the bioavailability of drugs. Product life extension and one of the disadvantage is toxicity. Toxicity of silver nanoparticles is mostly determined in vitro with particles ranging from approximately 1–100 nm. Silver nanoparticles are synthesized by various methods like physical method, chemical method like chemical reduction, microemulsion technique and UV-initiated photoreduction, photoinduced reduction, electrochemical synthetic method, microwave-assisted synthesis, bio-based method like bacteria, fungi, algae, and plant. In mechanism of silver nanoparticle, the nitrate reductase is an enzyme in the nitrogen cycle responsible for the conversion of nitrate to nitrite. During the catalysis, nitrate is converted to nitrite, and an electron will be shuttled to the incoming silver ions. Silver ions are very reactive and are known to bind with various vital components of the cells inducing cell death. Silver nanoparticle has various applications such as clinical and pharmaceutical applications, diagnostic and therapeutic application, pharmacological applications, and miscellaneous applications. Some marketed products of silver nanoparticles are available named as Disinfectant spray, Facial soap, Shampoo and Conditioner, Nanosil Toothpaste and Professional Hairbrush.