In the case of a reversible electrochemical reaction( reaction of your catalytic/sensing material or analyte) the cyclic voltammogram show the voltage peak to peak separation between the current peaks is 59 mV/n.   The ratio of the peak currents Ipa/Ipc equal 1.   But relatively larger peak current and the peak separation increases significantly when scan rate is increasing.       At potential scan rates higher, the peak to opeak separation increases, indicating the limitation arising from charge transfer kinetics.

In the case of a reversible electrochemical reaction( reaction of your catalytic/sensing material or analyte) the cyclic voltammogram show the voltage peak to peak separation between the current peaks is 59 mV/n.   The ratio of the peak currents Ipa/Ipc equal 1.   But relatively larger peak current and the peak separation increases significantly when scan rate is increasing.       At potential scan rates higher, the peak to opeak separation increases, indicating the limitation arising from charge transfer kinetics.

In the case of a reversible electrochemical reaction( reaction of your catalytic/sensing material or analyte) the cyclic voltammogram show the voltage peak to peak separation between the current peaks is 59 mV/n.   The ratio of the peak currents Ipa/Ipc equal 1.   But relatively larger peak current and the peak separation increases significantly when scan rate is increasing.       At potential scan rates higher, the peak to opeak separation increases, indicating the limitation arising from charge transfer kinetics.

Shen-Ming Chen thankyou for the valuable explanation. I was looking for, like if peak to peak separation is smaller then it has good catalytic property or sensing property or good selectivity. this sort of relation. 

Your word catalysis is confusing me. The smaller potential difference indicates a faster reaction, but this may not be catalytic at all, but simply that the electron transfer is inherently fast without any need for help by a catalyst.  Sometimes the word "mediator" is used to describe a second redox couple that facilitates transfer to the substance of interest - such as a redox active protein that would have a very slow electron transfer rate by itself.

Thank you Peter Kissinger, Actually I just joined PhD. I was allowed to select my field of research so i thought electrochemical sensors or something related to it would be good for my career. hence, I was thinking about this question, does it has any relation. like if it has smaller differences it would be good sensor or something like that. Thankyou

Generally the faster the electron transfer, the more selective a sensor will be at a lower potential... This however is rarely the biggest challenge..  Amperometric sensors have very few applications in the world outside of academia. By far the most important analyte is glucose in blood. Millions of measurements are made everyday.

Cyclic voltammetry is most useful for obtaining information about redox chemistry and materials. It is not very useful for sensing...

Hi, If you really want to use electrochemical sensing techniques to estimate, then by far the most useful method is Oscillating Square Wave Voltammetry. Normal Square wave or even Differential Pulse Wave is legit too for boosting the ip vs E signals of your redox reaction.

For background sensing tests between two compounds A and B where a redox reaction might occur, all these (CV, DPV, SWV, and OSWV) are used to monitor the reaction potentials, reversibility, number of electron transferred. Note that in accordance to Randles Sevick Equation (google up) the current has an inverse relation to temperature. So for cold redox reactions the current might boost up.

Now about your question. delta E is a quantitative parameter and sensing property is a qualitative term and hence there can be no relation (atleast mathematically). But the delta E ofcourse strongly depends on the number of electrons involved in the reaction.

To give a mathematical answer, see this

Delta E depends on number of electrons (vide Shen Ming's argument)

Number of electron depends on current (Randles Sevick eqn) (my argument)

More current means better sensing :) (ofcourse keeping other parameters constant)

Clearly number of electrons have a relationship to sensing. But as I already said, the relationship is quite indirect.

Hope u get a theoretical idea. Thanks

Agree. Most important of all is to have something worth sensing where electrochemical approach has a real advantage over all the other means.. this is the biggest challenge.  Typically, other technologies have much better performance to do the analytical job...

thanks alot Saunak Das. 

delta E changes with sweep rate - please see my papers more than 5 in JOURNAL OF POWER SOURCES 1988- 1991

You can find the answer for your question in my two papers:

1. J. Nieszporek

”Influence of sodium 1-decanesulfonate on the enthalpy of activation of two-step Zn2+ ions electroreduction”,

J. Electroanal. Chem. 662, 407-414 (2011)

2.J. Nieszporek, K. Dagci

”Influence of N-octanoyl-N-methylglucamine and N-decanoyl-N-methylglucamine on the kinetics and mechanism of Zn2+ ions electroreduction”

Electrochim. Acta 125, 473-481, (2014)

Thank you for your interest,

J. Nieszporek

Please contact cecri.res.in library mr.gunasekran

Values of Delta E explain the different electrochemical  properties of the analyte. 

Remember:  cyclic voltammetry theory is interesting for textbooks (such as mine), but reality is typically much different.  Nature often doesn't behave according to the theory for "ideal" redox couples which are very few.

Since1980i published about 150papers in all intternational journals  google my name v.s.muralidharan

The measurement of delta E with respect to the change is scan rate can be used for deducing the electro-kinetic parameters such as heterogeneous rate constant, number of electrons transferred etc. For more information kindly check sensing pprs  which calculated the kinetics using lavirons model.

Thankyou everyone for your kind support.

You are welcome. CV is good to study a material or process, but is not itself useful as a sensor. Too many things are changing  at the same time...time, potential, current, surface capacitance,...

 How to calculate the number electron transfer and reversibility using delta E