Figure 6.

Bactericidal activities of Ag-ND@BSA-embedded agar plates. (A) Bacterial growth inhibition testing of Ag-ND@BSA embedded in agar plates for Gram-positive and Gram-negative bacteria. E. coli and S. aureus were cultured separately on agar (a, b) and Ag-ND@BSA/agar (d, e). Streaked bacteria from (a) and (d) were sub-cultured in fresh LB broth for another 18 h, showing bacterial growth in (c) and (f), respectively. (B) Bacterial growth inhibition testing of Ag-ND embedded in agar plates for E. coli. In contrast to the result of Ag-ND@BSA/agar (a), colonies clearly formed in the regions containing Ag-ND aggregates (b), showing the failure of preventing bacteria from proliferation. Bacterial growth appeared when streaked bacteria from (b) were sub-cultured in fresh LB broth for another 18 h in (c). The LB-supplemented agars in both experiments were mixed with 250 µg mL⁻¹ Ag-ND@BSA or Ag-ND to form plates.