Silver Nanoparticle Synthesis and Luminol Catalysis

Recipe for making silver nanoparticles and a follow up experiment to check their catalytic properties.
Silver nanoparticles are made by mixing silver nitrate with a reducing agent. In this reaction, 0.001 M AgNO3 (10 mL) is added dropwise to 0.002 M NaBH4 (30 mL). If the Ag nanoparticles are not going to be used quickly after, a small amount of 4% polyvinyl alcohol can be added to cap the nanoparticles and limit aggregation. The PVA will bond to the surface of the nanoparticles and prevent them from merging together.
Every solution used must be with distilled water.
The second part of the experiment uses the silver nanoparticles as a catalyst for the reaction between luminol (0.01 M in 0.1 M NaOH) and potassium ferricyanide (0.1 M). The chemiluminescence is brighter and fades faster for the solution with the silver nanoparticles added.
The nanoparticles can be sized using a spectrophotometer by looking at the peak wavelength as well.