CHEMICAL SYNTHESIS OF COPPER NANOPARTICLES AND ITS ANTIBACTERIAL EFFECT AGAINST GRAM NEGATIVE PATHOGENS

Abstract

In this study, copper nanoparticles (CuNPs) were synthesized using a chemical method involving the reduction of copper sulphate by sodium borohydride, while polyethylene glycol 6000 served as a stabilizer. Characterization of the synthesized nanoparticles was initially carried out by UV visible spectrophotometry and the maxima absorption was observed at 280 nm. Atomic absorption spectroscopy confirmed the concentration of the CuNPs in solution to be 19.60 ppm. SEM revealed the nanoparticles to possess a spherical morphology. The size of the nanoparticles was between 117nm to 873nm while their zeta potential was determined to be 0.2mV. Antimicrobial tests were done by the agar cup diffusion assay and the macro broth dilution assay. Antibacterial activity of the synthesized copper nanoparticles was tested against common Gram negative pathogens, E.coli, S.typhi and V.cholerae. The ratio of the minimum inhibitory concentration and minimum bactericidal concentration of the particles was equal to one for all three test organisms, indicating CuNPs to be a good bactericidal agent.