I would suggest usage of poly-L-Lysine

Dear Yaroslav

For Gold electrode, should I use Thiol for modifying the surface first, after that is Poly-L-Lysine? How long does it take for that protein combine the surface of gold?

Thank you so much for your answer

Best regards

Anh

Dear Anh!

You can find answer to you question in one of the recent publications (Journal of Colloid and Interface Science 344 (2010) 150–157, Sensors and Actuators B 135 (2009) 642–649), Perhaps, you will be interested in some additional information on poly-L-Lysine (Colloids and Surfaces B: Biointerfaces 87 (2011) 299– 309).

Majority of Authors claiming that you need 12 hours forr Au electrodes treatment by SH-containing compounds, but I think after only 2-3 hours you will get the maximal level of gold surface coverage - for MUA pretritment, surely.

With very best regards.

Yaroslav.

P.S. By the way, your family name is the same as for many friends of mine i do have in Vietnam!

Dear Yaroslav

Thank you so much for your help. Have you ever been used this protein for enhancing the attachment of cell. I would like to ask you that, based on your experience, if we you this kind of protein, how long does it take for cell can attach, spread on top of gold electrode?

In the literature related cell experiment, authors normally monitored cells in the devices for long time (from 10 to 30 hours). In our case, I would like to reduce the time for cells attach on top of gold electrode.

If you have experience, please help me.

Best regards

Anh

P.S: Have you ever been to Vietnam? I know, until now, there are a lot of Vietnamese came to your country to study and work. My Family name is very popular in my country.

Hi Anh!

Actually I did not use poly-L-Lysine for cells (only for enzymes and this work is still under way), but I know from the literature it is the most often used methodology for proteins and cells. In your case it will depend on the cell surface charge - if negative compounds dominating - this methodology is very sufficient. When positive - you should look for another than poly-L-Lysine molecule. Anyway, just try. Another suggestion could be:

1. Cover your gold electrode with poly-L-Lysine (concentration 0.5% normally) during 3 hours.

2. Deposit your breast cancer cells on the electrode and dry it for 10-15 min (of course if you are sure it will not damage cells).

3. Cover your bi-layer sandwich with 0.5-1.0 % NAFION (negatively charged).

Kind regards.

Yaroslav.

P.S. I was in Vietnam just once, in 2009 and spent there ten absolutely amazing days - some of my friends said that I tried during this period a lot of foods they never eaten before - field mice, for example. There is also one fruit (I do not remember name) – majority of Vietnamese hate due to its smell, but the taste is unforgettable.

Thank you so much Yaroslav. I will try to do like your suggestions.

Best regards

Anh

Anh! You are welcome anytime.