Hello Amirmansoor Ashrafi ,

Can you tell us what polarization value are you applying to both probe and substrate?

Best regards

Emmanuel Mena-Morcillo

Hello

Thank you so much for answer. The parameters used in CV and probe approach vurve are attached. Also I attached the configuratyion which I use .

Thank You so much

Best wishes

Amir

Hello again,

Thank you for explaining your experimental setup. I have a couple observations regarding to what you send:

1.- I think you should improve the response of your microelectrode. It must show a steady state current (related to your mediator oxidation) when you run the CV. In order to achieve that, I will suggest to check that your microelectrode tip is clean and it has the right geometry (disc), with a good RG value. Also, I would suggest to change your potential range from -0 V to +0. 6V.

Here is a link that shows a good example of CV for the mediator that you are using:

https://www.edaq.com/teaching-application-2-electrochemistry-cyclic-voltammetry-of-ferrocene-carboxylic-acid

2.-You may change some parameters for the approach curve, for instance:

Probe E(V) to 0.6

Max Incr(um) to 1 or 2

Withdraw distance (um) to 100 or 200.

Being further from the substrate and having a smaller step size might let you see the approach curve with more points, and thus with a better resolution to detect additional issues, if any.

I really hope that everything goes well. Kind regards.

Emmanuel Mena-Morcillo

Thank you so much for your suggestion .

I tried every parameter but it did not help me. To observe the problem which I am facing I recorded a video . Please see the current manitude at quiet time and after it. is it possible to observe such a big jump just in the beggining of the scan. (scan was only in Z direction). Because I have never had the oppurtunity to attend in any training course for this instrument and it was not being used for some years I am afraid that there is something wrong with it .

Thank you for your responses

Best regards

Amir

Hello,

I saw what you mean. At what Z distance are you positioned and how did you do it? It does look a little bit strange.

Emmanuel

Hello

I put the tip far from the substrate (very far) and I did it manually it means I used the XZY control and put the tip by pressing Z up and when it was very far from the substrate I started the scan. Any way I tried different positions of Z but they all had the same problem

Thank you and best wishes

Amir

Hi there,

Why don´t you try to test the equipment with a well known system (Pt substrate in KCl solution for instance)? This would be in order to discard problems with the SECM. By the way, What is your subtrate?

Emmanuel