FIG 7.
Antimicrobial and catalytic assays reveal that bimetallic nanoparticles have the combined functions of their monometallic counterparts. (A) Average zone-of-inhibition data for Ag-AgNPs and Au-AgNPs from agar well diffusion assays with D. radiodurans and E. coli. Each well contained 40 μg of nanoparticles, and chloramphenicol (10 μg for D. radiodurans and 25 μg for E. coli) was used as a positive control. 1 and 2 denote addition of 0.1 mM metal stressor and 1 mM metal stressor, respectively. A zone of inhibition was not detected (ND) for either bacterium after treatment with 40 μg of Ag-AuNP 1 or Ag-AuNP 2. (B) Time-dependent UV-vis spectra for the catalytic reduction of 4-NP by NaBH4 in the presence of Ag-AuNPs. Data represent the mean ± standard deviation of three replicates. **, P < 0.01; *, P < 0.05.