A Ferritin Photochemical Synthesis of Monodispersed Silver Nanoparticles That Possess Antimicrobial Properties

Figure 4

Size exclusion chromatography of the ferritin AgNP solution. A standard of ferritin was passed over the column, and the elution profile was monitored at 280 nm (red). Ferritin runs as a dimer and monomer so it has two peaks. A sample of AgNPs synthesized photochemically by ferritin was passed over the column, and the absorbance was monitored at 280 nm (detecting the protein) and 420 nm (detecting the AgNP plasmon resonance). The AgNPs (420 nm peak, blue) and the ferritin (280 nm peak, green) coelute (~8 min) and are significantly shifted to an earlier elution than the ferritin standard (red), indicating that the particles are attached to the external surface of the protein shell. The presence of AgNPs also appears to shift the ferritin into the dimer species. Note: the absorbance dropping below zero is due to the changes of buffer composition compared to the blank.