2. Experimental Section
2. 1. Preparation of Silver Nanoparticles
The silver nanoparticles used in this study were
prepared by chemical reduction of silver compounds,
following a method used by Link et al. (1999) with a minor
modification. 0.0043 g silver nitrate (AgNO3, from SigmaAldrich,
ACS reagent) was dissolved in 95 mL de-ionised
water (Millipore, 18 MΩ-cm). The resulting solution was
heated by a hot plate to boiling point whereupon 5 mL of
sodium citrate (1% w/v, from BDH Chemicals) was added.
The solution was then refluxed for 30 minutes and turned
into the AgNP suspension. After the suspension temperature
decreased to room temperature, it was stored in the dark at
4-8 0C before use. AgNPs produced by this method were
found to have a lateral size in the range of 5-35 nm,
determined from the images from a high resolution
transmission electron microscope (HRTEM) (JEOL 2100F
FGETEM) at Durham University