Electrochemical behavior and determination of guanosine-5′-monophosphate on a ionic liquid modified carbon electrode

A carbon ionic liquid electrode (CILE) was constructed by using ionic liquid 1-butyl-3-meth-ylimidazolium dihydrogen phosphate, (BMIM)H2PO4, as modifier and further employed as a novel working electrode for the determination of guanosine-5′-monophosphate (GMP). The study of electrochemical behavior of GMP on the CILE showed a single well-defined irreversible oxidation peak on the cyclic voltammogram. Under the selected conditions the oxidation peak current was proportional to GMP concentration in the range from 5.0 to 1000 μM with the limit of detection of 1.3 μM (3σ) by differential pulse voltammetry. The proposed method showed good selectivity to the GMP detection without the interferences of coexisting substances.