Hello Vimala Anjuran ,

I would like to help but could you be more specific please?

What type of electrodes are you working with (glassy carbon, platinum, copper)? In which system are you working in (2-electrode, 3-electrode)? How did you modify your electrodes (SAM, polymers, ...)? What type of electrochemical measurements are you performing (EIS, CV, ...)?

With more information it will be easier to help you.

Best regards,

Marie Berthuel.

I completely agree with Marie, more information is needed to help you.

In CV technique, a modified electrode will provide more peak current if you modify it to increase its surface or you dope it with a catalyst.

In addition to the quest for more details, the nature of the material used in the electrode modification is very critical. While, it will be generally expected that a modified surface would yield much lower current peak due to charge transfer 'obstruction', certain materials e.g nanoparticles, quntum dots or graphene delivering more conductivity and specific surface area to the underlying electrode would lead to an increased current peak. Notwithstanding, more details are still necessary to fully understand the problem.

I am working in 3-electrode system. Glassy carbon,platinum and silver electrode as the working , counter and reference electrode respectively.I modified the electrode with aqueous solution of MWCNTs (ie., MWCNTs dispersed in water). I carried out CV, LSAV, SWAV and DPAV.@ Marie Berthuel

Respected Sir/Mam,

Thank you for ur valuable response. With ur kind intimation herewith I've given more details to fully understand the problem. I am working in 3-electrode system. Glassy carbon, platinum and silver electrode as the working , counter and reference electrode respectively. I carried out the studies with the working electrodes of bare GCE and the MWCNTs modified GCE. I modified the electrode with aqueous solution of MWCNTs (ie., MWCNTs dispersed in water). I've taken CV, LSAV, SWAV, DPAV to analyse the heavy metals in seaweed . In all the four techniques Pb, Cu ,Cr & As are present in the seaweed in the electrolyte of buffer. The peak currents for Pb, Cr and As are higher for the MWCNTs modified glassy carbon electrode than the bare glassy carbon electrode by the four techniques . Its correct. But the peak current of Cu is found to be lower for the same modified electrode than the bare electrode by CV, LSAV, SWAV, DPAV at the same run.The result is ok. But, what is the reason?

Respected Sir/Mam,

Thank you for ur valuable response. With ur kind intimation herewith I've given more details to fully understand the problem.

I am working in 3-electrode system. Glassy carbon, platinum and silver electrode as the working , counter and reference electrode respectively. I carried out the studies with the working electrodes of bare GCE and the MWCNTs modified GCE. I modified the electrode with aqueous solution of MWCNTs (ie., MWCNTs dispersed in water). I've taken CV, LSAV, SWAV, DPAV to analyse the heavy metals in seaweed . In all the four techniques Pb, Cu ,Cr & As are present in the seaweed in the electrolyte of buffer. The peak currents for Pb, Cr and As are higher for the MWCNTs modified glassy carbon electrode than the bare glassy carbon electrode by the four techniques . Its correct. But the peak current of Cu is found to be lower for the same modified electrode than the bare electrode by CV, LSAV, SWAV, DPAV at the same run.The result is ok. But, what is the reason?

@ Marie Berthuel

Jordi Carrillo Abad

George Ayankojo

The response obtained between ions in the solution and the working electrode depends on the relationship amongst them, that is, maybe your modified glassy electrode works good for Pb, Cr and As determination, because it exists a strong interaction between the WE and these ions but it becomes weaker for Cu ions.

Thank you Sir for ur immediate response. I agree with your answer. You h've told that there is a interaction between the WE and these ions but it becomes weaker for Cu ions. My question is again the same. Why there is a strong interaction between only selected metals (ie., Pb, Cr and As )? Why it is not possible for Cu?@ Jordi Carrillo Abad