I am developing an electrochemical sensor using screen-printed carbon electrodes.
Is it sufficient to mention the sensitivity of the sensor as the slope of the calibration curve or do I need to mention it as the slope/surface area of the WE?
The electrode area is relevant during the research phase, but only if you compare sensors with different geometry. For a given set of electrodes used for a new analytical application, slope is enough.
Thus, for a given sensor or sensors with the same geometry, sensitivity = current/concentration (i.e., slope). Mention the surface area for information.
But it is a better option, for comparison with similar studies, to report sensitivity as current density/concentration (i.e., slope/surface area).