I need to calculate sensitivity of modified Pt electrode. For this, I need slope (which I got from calibration curve) and area.
Can anyone please tell, how to calculate area to be used here.
You are looking for current density comparisons? Use the surface area of a disc/cylinder depending on the geometry of your sensor.
The area of one circle is πr2 and for a cylinder 2πrh (curved surface area), depends on the shape of the active surface of your modified electrode. Hope this helps.
Hi Shveta
Slope from calibration curve is equal to the sensitivity. However, divide the measured current by the area of the electrode to get current density, which is easier to make comparison to other previous reports. In this case, geometrical area need to be used as MS Saidhbhe mentioned.
Thanks.
Dear Shveta
The slope of calibration plot is sensitivity of your assigned electrode, hence, you directly divide by your electrode area (for example: 3 mm electrode surface area is 0.07 cm2) you may get the sensitivity in the unit of µA µM-1 cm-2.
Thanks for your answers.
I am a bit confused in this, I am using modified Pt electrode and have plot calibration curve between current and conc of analyte
For example, the Slope is 0.184. what would be the sensitivity then?
Generally, The slope of calibration plot is sensitivity of your modified electrode, the unit is µA µM-1. Sometimes ,the sensitivity of your modified electrode was obtianed by k/A. K is the slope of calibration plot, and A is the surface area of your modified electrode, the unit is µA µM-1 cm-2 . In many papers, the geometrical area of the bare electrode was used as the surface area of modified electrode for the related evaluation. In fact, The surface area of the modified electrode is changed by modified materials, thus the electrochemical active surface area of the modified electrode was used as real surface area, which can be calculated by many methods like CVs,EIS, CA, CC.
(1) https://www.researchgate.net/post/How_to_calculate_the_electrode_area_in_CV_measurements
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