Figure 7.

UV–vis spectra of AuNPs colloid against pH (a) and NaCl (b). The pH in a are (1) 0.2, (2) 2.0, (3) 4.7 (pI), (4) 9.0, (5) 13.0. The pH of gelatin-AuNPs colloid was adjusted by 0.01 M NaOH and HCl solution; The concentrations of NaCl in b are (1) 0.9%, (2) 2%, (3) 4%, (4) 8%, (5) 10%, (6) 12%, (7) 36.5%.

Liu et al. Nanoscale Res Lett 2011 6:22   doi:10.1007/s11671-010-9756-1