To investigate the sensibility effect of the biogenic Ag-NPs toward Pb2+ and Cu2+metal ions, lead and cupric ions solutions with concentrations of 10-3, 10-4 and 10-5 M were added to the Ag-NPs solution.For example, the addition of 10-3 M of Pb2+ resulted in a bathochromic shift of the plasmon absorption of 14 nm, from 400 to 414nm; however, with less concentration of the metal ions the shift diminish, from 400 to 411nm and from 400 to 408nm with concentrations of 10-4 and 10-5 M, respectively.These results are shown in Figure 7.