[3dem] Graphene Oxide grids hydrophobic

[Joey Davis]

Dear all,

In case folks find it useful, we recently described a simple, 3d-printed
jig to assess grid hydrophilicity by measuring the contact angle of a
droplet of buffer, as Kadir mentions.

A preprint including that protocol is here:
Application of monolayer graphene to cryo-electron microscopy grids for
high-resolution structure determination
Andrew V. Grassetti, Mira B. May, Joseph H. Davis
bioRxiv 2023.07.28.550908; doi: https://urldefense.com/v3/__https://doi.org/10.1101/2023.07.28.550908__;!!Mih3wA!B5bcwFrpxRf-x1T_JvaAS-N_6UhHXBF8MstLq8p0R-GqPFrnd550vUHAPPD7RPuNtO8YxhZ_KZ3kPIn2FmM$ 

and the peer-reviewed manuscript here:
J. Vis. Exp.(201), e66023, doi:10.3791/66023 (2023).

There, you'll also find a practical protocol for making graphene grids
following the method of Han et al. (PNAS 2020), and for rendering these
grids more hydrophilic via UV/Ozone treatment.

Cheers,
Joey

On Fri, Dec 8, 2023 at 3:03 PM Ozcan, Kadir Ali <kozcan at purdue.edu> wrote:

> Hello Dario,
>
> It is natural for GO grids to be hydrophobic despite GO's hydrophilic
> functional group content. As you and others have suggested, a short glow
> discharge can render grids hydrophilic however may potentially damage the
> GO layer. A safer way to render grids hydrophilic is exposing them to
> ozone. Our lab uses a cheap ozone generator we purchased on Amazon, the
> product name is "Aqua-6, 120 mg/hour Water Ozone Generator" from the A2Z
> Ozone Store (no affiliation). Place your grids in a petri dish or other
> small container with the ozone output source close to the grids for 15-60
> minutes. You can empirically determine the optimal time for your grids and
> assess hydrophilicity by adding water/buffer. In my experience 30 minutes
> is typically long enough. Additionally, adding a UV light source directed
> towards the grids in tandem with ozone may improve hydrophilicity. Let me
> know if you have any questions.
>
> Best,
>
> Kadir Ozcan
> PhD Candidate at Purdue University
> Wen Jiang Lab
>
> ------------------------------
>
> Message: 4
> Date: Thu, 7 Dec 2023 17:48:21 +0100
> From: Dario <dariobrack at googlemail.com>
> To: 3dem at ncmir.ucsd.edu
> Subject: [3dem] Graphene Oxide grids hydrophobic
> Message-ID:
>         <CAHOoyBO3zhtgTyaeCtgAmVY7ykCqE2EzSMNe-0Kw+CGbH9i=
> oA at mail.gmail.com>
> Content-Type: text/plain; charset="utf-8"
>
> Dear all,
>
> I have ordered commercial GO grids (QF 300 Cu R2/2 GO) and expected them
> to be hydrophilic out of the box due to the GO layer.
> However, the grid was not covered by the 3ul sample drop and appeared
> quite hydrophobic. How do you prepare the GO grids for plunging?
>
> I plasma cleaned them with air for 8sec, after that they were very
> hydrophilic, but I am afraid I might have destroyed the GO layer.
>
> Best
>
> Dario
>
>
>
>
> _______________________________
>
> Dr. Dario Saczko-Brack
> Postdoc
>
> Ludwig-Maximilians-Universit?t M?nchen
> Department of Cellular Physiology
> Biomedical Center Munich - BMC
> Gro?haderner Str. 9
> D-82152 Planegg-Martinsried
>
> Prof. Dr. Claudia Veigel
>
> Room: N.C 01.033
> Phone: +49 (0) 89 2180 71588
> Fax: +49 (0) 89 2180 71732
> Email: Dario.Saczko-Brack at med.lmu.de
> -------------- next part --------------
> An HTML attachment was scrubbed...
> URL: <
> http://mail.ncmir.ucsd.edu/pipermail/3dem/attachments/20231207/f60ab2a5/attachment-0001.html
> >
>
> ------------------------------
> _______________________________________________
> 3dem mailing list
> 3dem at ncmir.ucsd.edu
> https://mail.ncmir.ucsd.edu/mailman/listinfo/3dem
>


-- 
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Joseph H. Davis
Whitehead Assistant Professor of Biology
Associate Member, Broad Institute
Massachusetts Institute of Technology
77 Massachusetts Ave.
68-671A
Cambridge, MA 02139
617.258.6154
https://urldefense.com/v3/__http://www.jhdavislab.org__;!!Mih3wA!B5bcwFrpxRf-x1T_JvaAS-N_6UhHXBF8MstLq8p0R-GqPFrnd550vUHAPPD7RPuNtO8YxhZ_KZ3k_AaIVjo$ 
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mail.ncmir.ucsd.edu/pipermail/3dem/attachments/20231208/e5d2f832/attachment-0001.html>