Week 1, Starting SURI

This post covers what happened each day in the exciting life of a chemistry researcher during the week of 5/23-27/16.

The first day

Made a double batch of gold nano-particles (hereby referred to as AuNP) and put them in a centrifuge to spin at 8000 rpm for 15 minutes
- It looks like it plated the centrifuge conical, maybe will do at 5000 rpm for 20 min next time
- Put DI water in conical to make a total of 20 mL of liquid to re-suspend the particles

Day two

Made another double batch of AuNP
- Spun at 5000 rpm for 10 minutes (that failed)
- Shook t re-suspend then put in at 6500 rpm for 15 minutes, looking good
- Sonicated briefly to dislodge gold on the sides of the vial
- Filled to 20 mL with DI

Finished APTES procedure on 11 vials and put on rotator to coat overnight. (rotation perpendicular to axis of the vial)
- Half had the AuNP from the 8000 rpm spin, and half had AuNP from the 6500 rpm spin

Day 3

Vials not looking good, only one looks like it might actually work but it looks like it did nothing. Putting that one in the sonicator for a bit.

Made up 12 new vials with APTES
- Using the new vials with white caps and polymer sealant instead of the black caps with a foil seal
- Did not use aqua regia since they are brand new

Made up 4 glass slides with APTES
- Going to use to figure out packing density and enhancement factor
On the vials from yesterday
- The gold has either precipitated out or attached to the foil lid
- Rinsed with DI and left to dry
- Doc Bantz thinks that decanethiol might be our best bet for surface enhancement of the gold
Will make 3x batch of AuNP
- Will put in the new vials
- 6 total
  - 2 at full strength (4 mL AuNP)
  - 2 at half strength (2 mL AuNP)
  - 2 at 1/4 strength (1 mL AuNP)
- Will put in rotator overnight (rotation in line with the axis of the vial)

Have one extra APTES ready vial from yesterday, will suspend in sonicator to try and root out why the vials failed. One of the following caused the problem:
- APTES error
- Centrifugation
- Rotation instead of sonication

Day 4

The vial from the sonicator plated properly
NO MORE SPINNING AuNP IN CENTRIFUGE
Set up a vacuum system to speed production of APTES vials
- can now do 32 at a time instead of only 10

Initial look at vials in rotator looks good
Shot Raman of yesterday’s seemingly failed batch (except #2 because it is still not plating or precipitating out)
- Vial 11 was the one that was sonicated
- Vial 2 was abandoned
- Scrapped and aqua regia’d ll the vials
Calculated out the amounts of material needed to make 10 mM decanethiol in ETOH and then made it
Took vials out of rotator. All six are looking good.
- Rinsed in DI and put in decanethiol and let sit overnight

Day 5, wrapping up for the weekend

The vials with decanethiol were washed with DI water and it destroyed the plating. They went from a nice dark purple with a gold shine to clear vials. Raman confirmed that all was lost.
- Might rinse in ETOH rather than DI next time
Put another 6 vials in rotator with same concentration setup at 10 rpm
Took vials from 4/7/16 (Chemistry FTX) to test if they are losing their qualities over time with a decanethiol enhancement. Raman proved that they are very stable.
- A and E will be kept as stability testers (A with DI and E in air)
- The remainder will be used to detect m-xylene

Shot Raman of a clean vial with m-xylene in it to get a baseline
Calculated the materials needed to make a 1 mM solution of m-xylene in ETOH then made up 50 mL of it
Did the first test with the xylene on the vial from 4/7 labeled F with 1 mM solution of m-xylene
- Put in 2 mL m-xylene, shook for 30 seconds and let sit for 5 minutes
- Emptied and let dry for 10 minutes
- Didn’t give any significant signal
Took vial 11 (with benzenethiol) and shot baselines
- Did the same as above with m-xylene
- Looks like the signal isn’t there still

Michael Parsons