I would be grateful if someone can suggest an analyte that works very well with gold nanoparticles and not so well with silver nanoparticles.
I would suggest Rhodamine 6g to study it's adsorption on AuNPs and AgNPs.
With respect to the sub-question : Analytes containing nitrogen groups, thiols and phosphines will effectively adsorb onto AuNPs. These groups can also bind to AgNPs, but analytes containing carboxylate groups and amines should bind more effectively on AgNPs as compared to AuNPs.
Thank you @Sachin Nair. I am actually looking for something that works or absorbed exclusively on AuNPs as compared to AgNPs.
Dear Sampson, I found this article which may be of help for you.
https://res.mdpi.com/nanomaterials/nanomaterials-03-00158/article_deploy/nanomaterials-03-00158.pdf?filename=&attachment=1
Quoting from rom the paper “The effect of the irradiation time on the enhancements obtained in the SERS experiments using the metallic NPs prepared was evaluated using 4-ABT for Ag NPs. Similarly, 1,2-bis(4-pyridyl)ethylene (BPE) was used to evaluate the optimum conditions for the synthesis of Au NPs. These analytes were selected based on the affinity of the compounds with the corresponding NPs”.
Although,in my limited knowledge, I don’t know any molecule that adsorbs onto Gold and doesn’t adsorb at all on silver.
Best,
Sachin
Maybe molecules with thiol-groups could be worth of trying... They should attach to gold surface but not to slightly oxidized silver surface.