Synthesis and characterization of diamond–silver composite with anti-bacterial property

•Silver nanoparticles (AgNPs) with narrow size distribution were directly produced on nanodiamond (ND) surface.•AgNO3 was used as Ag+ source and polyvinylpyrrolidone (PVP) used as reducer.•The in-situ reduction/deposition process was confirmed by UV–vis absorbance, XRD and TEM results.•The as-prepared Ag/ND composite showed efficient anti-bacterial property against E. coli.

Diamond–silver composite has been successfully prepared through an in-situ reduction/deposition method by using AgNO3 as Ag+ source and polyvinylpyrrolidone (PVP) as mild reducer and stabilizer. Synthetic nanodiamonds (NDs) were used as support material. TEM results confirmed that Ag nanoparticles (AgNPs) with a narrow size distribution were uniformly immobilized on NDs surface. XRD and UV–vis absorbance results proved that most AgNPs were formed on NDs surface rather than in solution. Finally, the anti-bacterial ability of as-prepared Ag/ND composite against Escherichia coli (E. coli) bacteria was determined, and the results showed that, with only 6.6×10−4 wt% of Ag/ND in medium, the growth of bacterium E. coli was almost inhibited.