Controlling inter-sheet-distance in reduced graphene oxide electrodes for highly sensitive electrochemical impedimetric sensing of myoglobin

[Display omitted] •Impedimetric sensitivity was improved by enlarging electroactive surface area.•Electroactive surface area was tuned by varying inter-sheet distance between rGOs.•Detection limit of electrochemical myoglobin-sensors was 2.37 pM.•High selectivity for myoglobin detection over other heme groups was confirmed. In order to improve the sensitivity of electrochemical impedance spectroscopy (EIS)-based biosensors, a number of structuring strategies to promote enlarging the electroactive surface area have been recently proposed. However, these approaches have not been applicable to graphene-based electrodes especially due to their ultrathin film thickness (usually