Is it recommended to polish the Glassy Carbon Electrode (GCE) with alumina and diamond slurry prior to its usage or is it possible to use it without polishing?

Yes, polishing of GCE is highly recommended prior to the experimentation using alumina and diamond slurries to obtain clean and uniform surface. Also, to remove the residues of the previous experiments. In this way, the repeatability, sensitivity, and stability of the electrode can be improved. It could be feasible to utilize a GCE without polishing but the surface of the electrode is awry, which could lead to inconsistent electrochemical performance.