Manufacturing high-density graphene edges with electrochemical etching for sensing aminophenol

In this study, an electrochemical etching method were proposed to manufacture high-density graphene edges on the surface of N-doped graphene sheets embedded carbon (N-GSEC) films for sensing aminophenol. We found that the sp³-hybridized carbon and nitrogen atoms were more susceptible to be etched than the sp²-hybridized atoms, resulting in the decrease of amorphous and the formation of more graphene edges. These graphene edges with higher electronic density of states can be served as electrochemical active sites and accelerate the electron transfer rate. The etched N-GSEC film exhibited much better electrochemical activity for two redox probes of Fe(CN)₆^4-/3- and Fe^2+/3+ as well as the aminophenol molecules. It can be applied in simultaneous detecting the 4-aminophenol and acetaminophen in the liner concentration ranges of 0.1 μM-250 μM and 0.05 μM-100 μM with detection limit of 0.01 μM and 0.025 μM, respectively. The electrochemical etching of N-GSEC film opened a new avenue for manufacturing a surface with high-density graphene edges in electrochemical sensing.