Figure cyclic voltammetry shows no wave for GCE in the absence of any gold NPs and EtOH (voltammogram a-i). After adding 0.5 M EtOH this is observed an increase in the current intensity from 250 μA (voltammogram Ai) to 420 μA (voltammogram a-iii) at 1.497 V as well as formation of an oxidation wave at 1.35 V with the onset potential at 1.08 V.