This week is no longer focused on progression of the research, this is focused on preparing my presentation for SURI and analyzing the data collected.  That being said I think that some minor experiments will still be run, but nothing super complicated.

June 20

• The white capped vials might be the problem.  Were going back to the black capped vials, but this time the foil will be covered in parafilm to avoid the AuNP attaching to the foil.
  • Did APTES procedure, but blew dry the last step instead of baking
  • Put in rotator overnight
• Tried to wash xylene out of A1 and K1
  • Rinse 3x with ETOH + shaking – no
  • Shake ETOH then let soak for 30 mins – no
  • Put water back into the vials – no

June 21

• Looked at the vials in rotator, they look exactly the same as they did when I put them in.
  • Took the rack off the rotator and put it into the sonicator, hopefully this will do SOMETHING
    • Looking Good!
• Did my presentation to the department, now I just need to submit my paper!

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!

 

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.

This post covers what happened each day in the life of a high-speed low-drag operator in the chemical corps during the week of 5/31-6/3/16.

Tuesday the 31st

• Turns out that the failed vials from the sonicator didn’t work because the bottom of the glass vials broke and fell out (still have no idea where that broken glass went)

• Cleaned the sonicator of nano-particles
• The vials from the rotator in different concentrations are looking great. the 1/4 concentration (1 mL) vials look very nice and consistent.
  • Treated with benzenethiol so thy can be compared on Wednesday, let sit for 24 hours
• Put 6 more vials in rotator
  • 2 at 1 mL
  • 2 at 3/4 mL
  • 2 at 1/2 mL

Wednesday the 1st

• Took vials out of rotator, they don’t look as nice as the vials from Monday
• Rinsed benzenethiol out of the vials that were left to soak, let dry
  • Shot Raman that confirmed that the full strength and 1/4 strength vials were nearly identical
• Received hexanethiol in the mail (that vial is 5 mL and came in the box that it’s next to)

• Put in six vials at 1/2 strength (2 mL)
  • Will treat with a hexanethiol solution tomorrow if they look nice.

Thursday the 2nd

• Took Raman of vials that were treated with m-xylene
  • Took UV Vis
• Taking UV Vis of plain vials and vials treated with xylene to see if absorbance is different

• The vials in rotator are looking less than great
• Taking UV Vis of AuNP in a quartz cuvette in a 40% concentration in DI.  This is because I am concerned that the gold concentration is going down and causing issues in the plating process
• Made up 1 mM solution of hexanethiol in ETOH
• Put 4 mL AuNP in 6 vials to rotate overnight

Friday the 3rd, National Doughnut Day

• Took concentration reading of AuNP with UV Vis and it looks very similar to yesterday
• Took hexanethiol solution out of the vials from yesterday and took Raman reading.  Very weak signal but I think that it’s there, so I re-filled them with the 1 mM hexanethiol solution to sit until next week.  I know the coating isn’t messed up because the benzenethiol treated one worked great, it definitely has something to do with the hexanethiol.
• Vials in rotator will be put back in the rotator because they aren’t plating properly and the AuNPs in them are looking funny.  It should’t be that green-brown, it should be gold and purple.

 

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

• Started APTES on 12 vials (broke one), see the methods tab for details

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