Protein resistant coating of Au surfaces with PEG.

Hi,

I'm trying to find a good coating for Au surfaces to resist protein
adsorption. From the literature, it seems that PEG (polyethylene
glycol) forms a good protein resistant layer. I'd like to know what
the best ways to coat PEG onto Au are. Using PEG-terminated thiol
appears to be one way to do it.

Will I have to make the PEG-thiol myself or can I buy already
functionalized thiols which will be protein resistant?

Thanks,
Sanjay Vijendran