June 6th 1944 2016

• Drained hexanethiol out of vials again and shot Raman.  They still don’t look good, the signal is incredibly weak.
  • Baselining with a vial from Thursday full of hexanethiol rather than an APTES vial with hexanethiol.  Still not looking great even when I played with laser powers and integration times.
  • Did some research on alkanethiols attaching in a self-assembled monolayer (SAM) to gold.  Looks like it just takes a really long time for some of the alkanethiols to react and pack properly.  This paper says that it can take up to seven days to form properly, but it also says that three days was sufficient to give him a close-packed SAM.
• Took vials from Thursday out of rotator.  Going to discard, but they’re going to be subjected to a treatment of piranha acid to see if we can strip the APTES and AuNP in one step.
  • Close but not quite, will have to aquaregia then piranha.
• Running a new group of 6 vials
  • 2 will be cooked in oven at 100°C for an hour then filled with old AuNP (δ)
  • 2 will be cooked in oven at 100°C for an hour then filled with new AuNP (Λ)
  • 2 will be filled with new AuNP (Ω)
• Did UV Vis of new nanoparticles

• It’s Tappey Jones’ birthday!  We ended up buying him a cake, card, and a balloon and getting the entire chem department into the break room to wish him a happy birthday!

June 7

• Talked to Doc Bantz about the UV Vis of the nano-particles and she said that they are definitely ripening and losing their usefulness over time.  We bought dialysis cassettes to keep the NPs fresh.
• Making another batch of 30-something APTES vials.  Upgraded the vacuum system to have a much bigger collection vial so this process is now exceedingly easy.

• Rinsed out rotator vials from yesterday and let dry in the hood overnight.
  • Lambda looks terrible
  • Delta looks alright
  • Omega looks AMAZING!
  • This confirms that the old AuNPs are going bad and dialysis is probably our best bet
  • Put one omega and one delta to soak overnight in hexanethiol

June 8

• Finished APTES of the set of 30-something vials
• Treated several vials with aqua regia and piranha then started the APTES procedure on them too.  Will mark to show that they have been piranha’d  to see if there is a difference between ones treated and untreated with piranha.
• Found a new paper that’s all about using 1-octanethiol and 1,10-decanethiol to make an even better SAM.  It says that is has proven to be able to trap biologics in the SAM and I think it may be great for what we are doing.  SUPER EXCITED AND I WANT TO TRY IT.
  • It lives here
• Saved lab 412 from Typhoon Carrick.  He flooded his hood and I brought my vacuum apparatus over to suck up all the water, it ended up being over eight liters of water in the hood!  Christened my vacuum apparatus ‘THUNDERBIRD-2’ because it saved Carrick’s lab from flooding and that’s my favorite ship from the old TV-show Thunderbirds.

• Shot Raman of vials soaked in hexanethiol from yesterday.
  • IT LOOKS FANTASTIC!
  • Going to try and detect xylenes tomorrow!

June 9

• Took the hexanethiol treated Ω vial and put in 1 mM soln’ of m-xylene
  • Shook gently for 30 seconds and let sit for 10 minutes
    • Didn’t detect
• Made up 1 mM soln’ of 2,4-D, a common pesticide.  Put in the same vial that the m-xylene went in since nothing attached.
  • The gold was stripped off.  It appears that the APTES was weaker than the forces of the hydrophobic hexanethiol and the APTES simply failed.  Still showed up on Raman though.  Still no detection of the 2,4-D

• Started 17 more APTES vials
• Received dialysis cassettes in the mail for the nano-particles, will try later
• Took vials out of rotator, don’t look great but will treat with hexanethiol and octanethiol (1mM) overnight.
• Going to try a layer by layer procedure tomorrow (see the procedures tab).  This uses a polymer to attach the gold in multiple small layers to build up a more robust coating.
• More upgrades to THUNDERBIRD-2
  • Added a small vacuum flask for smaller jobs that need to be put in waste jugs, like removing nano-particles or APTES leftovers.
  • Made a double connection to the trap flask so that both the large and small vacuum flasks can run at the same time and can avoid the hassle of rearranging the tubing to use the different flasks.

Friday the 10th

• Starting the layer by layer process for a set of vials
  • Got 8 layers on the .02% PEI
  • Got 4 layers on the .2% PEI

 

• IMPORTANT:  We think that the plastic pipettes have some sort of polymer on the surface left over from manufacturing that is causing the AuNPs to fall out of solution.  We will now only use glass pipettes for the gold to avoid destroying more of them.
• Made a 5x batch of AuNP and put in dialysis cassette, doc Bantz will change the Milli-Q water twice this weekend

• Shot Raman of the vials from yesterday
  • Octanethiol looks consistent and is showing up well
  • Hexanethiol is good but lacks consistency

• THUNDERBIRD-2 got called to service again in lab 412.  This time the Rotovap broke apart and dropped a huge portion of Carrick’s product into the water bath.  He’d been working on getting that product for almost all summer session.  We recovered two liters of liquid and he had to sep-funnel all of it to try and recover as much as possible.