The green synthesizing procedure of Silver nanoparticles (AgNPs) has been performed through the usage of a natural polysaccharide; Arabic gum (AG) as a stabilizing/ capping agent. For characterization of AgNPs, TEM, particle size analyzer and UV-Vis were used.The aim of our project was to identify biosynthesized AgNPs for sensing ammonia and to explore its toxicity on Neuro-2A cells. We also reviewed the patents for biosynthesized AgNO3 and ammonia sensing. The optimal conditions for the synthesis of AgNPs in AG consist of utilizing (0.1g) AG in dH2O (70 ml), 10 ml of 1 mM silver solution and 0.1 mM (AA) at 70°C stirring for 30 minutes. The AgNPs cytotoxicity was evaluated on Neuro-2A cells; consequently, ammonia was sensed with the lowest possible concentration of 10-6.Particle size analyzer displayed the mean diameter of about 70 nm for the sphericalshaped Ag-NPs. UV-Vis revealed that the prepared AgNPs were ammonia sensitive in solution as the concentration of ammonia was increased. The cytotoxicity of AgNPs indicated lower Cell viability at higher concentrations of the AG-capped AgNPs.By synthesis of AgNPs in GA by using AA, we successfully prepared a sensor to diagnose ammonia in a cell and sensing its level at concentrations of 10-6 M. In this study, no therapeutic application has been shown, but this method could be utilized industrially for therapeutic purposes in the future.