Highly Sensitive Electrochemical Detection of Azithromycin with Graphene-Modified Electrode

An electrochemical cell containing two graphite rods was filled with the appropriate electrolyte (0.2 M ammonia + 0.2 M ammonium sulphate) and connected to the exfoliation system to synthesize graphene (EGr). A bias of 7 V was applied between the anode and cathode for 3 h. After synthesis, the morphology and structure of the sample was characterized by SEM, XRD, and FTIR techniques. The material was deposited onto the surface of a glassy carbon (GC) electrode (EGr/GC) and employed for the electrochemical detection of azithromycin (AZT). The DPV signals recorded in pH 5 acetate containing 6 x 10(-5) M AZT revealed significant differences between the GC and EGr/GC electrodes. For EGr/GC, the oxidation peak was higher and appeared at lower potential (+1.12 V) compared with that of bare GC (+1.35 V). The linear range for AZT obtained with the EGr/GC electrode was very wide, 10(-8)-10(-5) M, the sensitivity was 0.68 A/M, and the detection limit was 3.03 x 10(-9) M. It is important to mention that the sensitivity of EGr/GC was three times higher than that of bare GC (0.23 A/M), proving the advantages of using graphene-modified electrodes in the electrochemical detection of AZT.

Automated summary

Graphene-modified glassy carbon electrode was successfully prepared through the synthesis of graphene in an electrochemical cell. The electrode exhibited higher oxidation peak and lower potential compared to bare glassy carbon electrode. The graphene-modified electrode showed higher sensitivity and a wide linear range in the electrochemical detection of AZT.