June 13

• Took AuNP out of cassette and put in APTES vials in 2 mL portions.  They appear to be reacting really quickly, the vials turned fairly purple after less than five minutes!

• Continuing to layer the PEI Vials (this is very time-consuming and I don’t think it’s working)
  • Got up to 14 layers on the .02% PEI
  • Got up to 10 layers on the .2% PEI

June 14

• Took UV Vis of .02% PEI vial, looks alright (top vial in picture)
  • Treating with benzenethiol to baseline

• Treating vials from rotator (APTES, AuNP)
  • Tested the pH to see if that’s causing issues, but they were all neutral

• • When washed with DI, it seemed as though some of the gold was pulled off (see below)

• Treating vials as follows
  • 3x Hexanethiol (Α)
  • 3x Octanethiol (Κ)
  • 6x PEI .02% + AuNP layer
    • 3x Hexanethiol (Σ)
    • 3x Octanethiol (Ω)

• Letting one APTES vial sit in the vial rack with AuNP in it.  Will test to see if rotation is helping
  • Marked with a (ψ)
• Took pH of AuNP to compare capped vs open air storage for a few hours
  • Open air – 4.50
  • Capped – 4.34
    • Acidified to 3.96
• Made Ag Dendrites (AgD)
  • The process is outlined on the methods page
  • Put AgD in APTES vials and let rotate overnight

June 15

• Making 30-something APTES vials
• Took the vials from yesterday and washed them out with ETOH, let dry in the hood
• The vial that was left to sit in the vial rack (ψ) looks ok on the bottom, sides leave a lot to be desired
  • treating with benzenethiol to baseline later

• The APTES vials and AgD didn’t work at all
• I noticed that all the vials that we are working with have a strange band along the bottom (see below), it appears to be hydrophobic and can prevent the AuNP from attaching properly.  It’s on all the vials, regardless of treatment.  not sure how this is effecting everything, but I don’t think it’s good.

• IMPORTANT: I think that the AuNP creation process does not scale-up, I might have to do them in batches of 13.9 mL.  The big batch was tan, the medium one was reddish, and the small ones are purple.  This might be causing the inconsistency.

• Made new batch of AuNP (13.9 mL) and put them in new APTES vials that I finished this morning
  • APTES was cooked without capping
  • Put in rotator overnight

• Shot Raman of Α,Κ,Σ,and Ω
  • Most are average
  • A couple are fantastic (maybe my new standard) and one is atrociously bad
• Made a video of the creation of silver dendrites, check it out under the methods tab!

June 16

• The vials in the rotator aren’t looking good.  Two are tan, two are purple.  Tested pH, but they are the same for both tan and purple

• Started APTES procedure on new batch of vials (cooked while capped)
• Found the vials that were suitable for detection out of the Α,Κ,Σ,Ω vials
  • Α – 1,2,3
  • Κ – 1,2
  • Σ – 2
  • Ω – 3
• Tried to detect m-xylene (1mM) using A1 and K1
  • Shook for 1 min ad let sit 20 mins
  • Nothing detected
• Tried to detect 2,4-D (1mM) using A1 and K1
  • Shook for 1 min ad let sit 20 mins
  • Nothing detected
• Will try to up the concentrations of m-xylene and 2,4-D to see if it can even detect at all
• Treated the vials from the rotator with decanethiol
  • will shoot Raman tomorrow then test to see if the DI water will strip it
• Made a single batch of AuNP and put them in 4 APTES vials that were made today
  • Put those vials in rotator at 20 rpm (instead of the usual 10)

June 17

• Took vials out of rotator from yesterday afternoon
  • Top and bottom look great, but the middle isn’t looking good

• Replaced the Milli-q water for the AuNP in the cassette
• Took decanethiol out of vials that were soaking.  Will shoot Raman to see if DI water strips the gold off like it did last time
  • 1 and 2 will get m-xylene in ETOH (1 mM)
  • 3 and 4 will get 2,4-D in DI (1 mM)

• The decanethiol did not detect anything, but it didn’t strip either.  I guess that’s kind of a win?  Glad the gold isn’t striping anymore.  I got that going for me, which is nice
• Made a 10 mM m-xylene solution in ETOH.  Re-treating the following vials
  • A1
  • K1
  • Dec 1,2
• The above didn’t work, so I took straight m-xylene and put it in the vials.  I swirled, vacuumed the xylene out, then filled with DI water to try and push the xylene into the thiols.
  • HEXANE AND OCTANETHIOL WORKED, THEY DETECTED PROPERLY!
  • Decanethiol did nothing
  • Below are the charts, Green is pure m-xylene, Red is the vial that I was testing (Top is Alpha 1 and bottom is Kappa 1), Blue is the baselines for the vials before treatment.  Observe the places where the green and red peaks are present and the blue is not, those are the peaks that prove that there is detection!