I am interested to deposit SERS gold colloids on a medium. This medium should allow the deposit of an analyte for SERS detection.
I have found a paper on this technique: "Inkjet printed surface enhanced Raman spectroscopy array on cellulose paper (Yu et al 2010)".
However, I've repeated this procedure and found that cellulose paper performs poorly for some analyte such as monosodium glutamate, benzoic acid, dimethoate and malathion. I am not sure why.
Can you guys recommend me some material to try?
I am not sure what you expect from the medium. For high SERS you need the molecule to be on the metal (gold for example): surface, or even better sit in a hotspot between particles. Therefore high SERS usually is seen for molecules that have high affinity to gold (such as aromatic thiols) and the substrate on which the gold sits is not that important.
For the Raman enhancement the surface below the nanoparticles I don't think matters. You could use a Silicon oxide surface for convenience, although the Si raman peak is strong (but if it's far from your features of interest that doesn't matter, and it's quite sharp). You could also try a Ti or Al surface to adhere the Au nanoparticles.
The support on which one can deposit the gold colloidal nanoparticles for SERS investigations must allow adhesion of the nanoparticles by solvent evaporation and not give Raman or fluorescence signal that can interfere with the observation of the SERS bands of the analyte. Foils of aluminum may be suitable for this purpose.
Hi, Ron is quite correct. SERS is a proximity effect and the analyte needs to be adsorbed close to the gold surface. Perhaps you should consider work being carried out by Volker Deckert , His research group has being carrying out excellent work on a technique called TERS (a synergy between AFM and SERS). This technique has made phenomenal progress in the last 5 years and is very promising (and being used at Imperial College); as you will see from the published papers listed in his web page at Jena University. The great thing about this technique is that you do not need the analyte to be adsorbed to the metal surface. This is because the AFM tip is coated in gold and moves over the surface of the analyte and Raman signals are picked up by the detector. Hope this helps.
- Badges
- Science topic
- Similar topics
- Physical Sciences
- Materials Science