The characteristics of the nanoparticles of silver, copper and zinc obtained from two synthetic routes were investigated. A possible future application of these nanoparticles is as bactericidal agents. The reduction methods were Aloe vera extract and gamma ray irradiation with a dose rate of 0.756 kGy/h and a total dose of 40 kGy from a 60Co-source. The chemical species of the nanoparticles (NPs) obtained by Aloe vera extract were Ag, CuO, and ZnO; while the NPs obtained using gamma irradiation were Ag and Cu2O. The precursor to obtaining the nanoparticles and the route of synthesis define the purity, morphology, crystallinity, and chemical speciation of the metal.