Formation of Highly Antimicrobial Copper Nanoparticles by Electroless Deposition in Water

Mary Donnabelle L. Balela, Kathy Lois S. Amores


Metallic copper (Cu)nanoparticles (CuNPs)with mean diametersranging from 37 nm to 44 nm were synthesized by electroless deposition (chemical reduction)in an aqueous solution at 353 K. Cupric oxide (CuO) powder, which has low solubility in water, was used as the Cu(II) precursor. Gelatin and hydrazine (N2H4) were employed as the protective agent and reductant, respectively. Small spherical Cu nanoparticles having mean diameter of 37 nm were formed using 2.25 wt% gelatin. In the absence of gelatin, large Cu nanoparticles of 377 nm in mean diameter were produced. Both cuprous oxide (Cu2O) and metallic Cu peaks were identif ied from the X-ray diffraction pattern of the samples. The results suggest that gelatin hinders the growth of Cu nanoparticles in solution and protects the nanoparticles from oxidation. Interestingly, the as-prepared Cu nanoparticles exhibit strong antimicrobial activity against Escherichia coli and Staphylococcus aureus.

Keywords: Copper nanoparticles, electroless deposition, hydrazine antimicrobial


Spherical copper (Cu) nanoparticles with average diameter in the range of 37-44 nm were formed by simple chemical reduction in water at 80°C. Gelatin was used to protect the Cu nanoparticles from oxidation and prevent their agglomeration in solution. In fact, larger Cu nanoparticles of about 377 nm in average diameter were produced when gelatin was absent in the solution. In addition, oxides of Cu (Cu2O) were observed in the X-ray diffraction pattern of the same sample.

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