Fig. 4.

a Cyclic voltammetry of 200 μL of 5 mM FCA at a scan rate of 100 mV s⁻¹. The artefacts (dotted circles) at V < 0.1 V seen for WE1 is due to epoxy used for wire bonding. b Chronoamperometry measurement with 200 μL of 5 mM ferrocene carboxylic acid with the inset showing the fitted data. c: I v/s t ^−1/2 plot obtained from chronoamperometry measurement with 200 μL of 5 mM ferrocene carboxylic acid