Figure 1From: A colorimetric method for the molecular weight determination of polyethylene glycol using gold nanoparticlesSchematic of two neighboring AuNPs coated with adsorbed PEG. RAuNPs is the radius of the AuNPs, L is the nanoparticle center-to-center separation distance, H is the separation distance between the nanoparticle surface (H = L − 2RAuNPs), and t is the thickness of the adsorbed PEG layer.Back to article page