Week 1
- Xylenes will not attach to an unmodified gold surface
- Getting close to fine tuning the concentration of the AuNP needed for rotation instead of sonication
- Discovered that decanethiol will not work for detection in water, need a shorter chain thiol to get results
- Setup an industrial level production method for making the APTES coated vials
Click here for lab notes for week 1
Week 2
- Something is off with the AuNP and they might be going bad much quicker than expected
- UV Vis is giving results that say that the gold is absorbing almost the perfect wavelength for the Raman laser
- Honing the coating process for the vials
Click here for lab notes for week 2
Week 3
- Baking the APTES treated vials before AuNP coating makes things worse
- The nano-particles are ripening and making the plating worse over time
- The thiols that we use are so hydrophobic that they dislodged the gold from the APTES coating on the vial
- IMPORTANT: Doc Bantz and I are pretty sure that there is some kind of polymer in the plastic pipettes that is destroying the AuNP, only using glass from now on
- Octanethiol is very consistent, will test how stable it is over the next couple months
Click here for lab notes for week 3
Week 4
- Vials treated with the LBL method and .02% PEI show up on UV Vis in the correct absorption band.
- Exposing AuNP to air slightly effects the pH, which can cause problems
- Ag dendrites are cheap and easy, but it isn’t clear on how they can be utilized in SERS yet
- As of now, there is no clear difference between dialyzed AuNP and normal AuNP
- IMPORTANT: Vials that were treated with APTES/AuNP/Hexanethiol and Octanethiol were finally able to prove that the SERS is working! The proof of concept was that once the vials were treated there were new peaks that weren’t observed when simply treated with the thiol. Even though full strength M-Xylene had to be used to see the signal, we proved that molecules like that can be trapped in the thiols attached to AuNP!
Click here for lab notes for week 4
Week 5
- Doc Bantz and I agree that the black capped vials are of much higher quality and we will only use them from now on, but we will still use the white caps on those vials because the foil and parafilm under the caps keeps melting and interfering with the reaction
- Will test whether pH of the AuNP has any effect on the plating process