The antibacterial activity of shell-Ag materials in liquid LB cul- ture of E. coli and S. aureus was investigated, respectively. Briefly, 25 mg of shell-Ag and 9 mL LB medium aqueous were mixed for autoclaving (15 min, at 121 °C); 1 mL bacteria suspension (10 6 CUF/mL) was then introduced into the above mixture and the final concentration of bacteria and shell-Ag were 10 5 CFU/mL and 2.5 g/L, respectively (the lowest level of MBC value). The aliquots of 100 μL were sampled at various time intervals and plated on the LB substrates for viable cell counts; the control experiments (blank test without shell-Ag addition) were also conducted as references.