Voltammetric myoglobin sensor based on a glassy carbon electrode modified with a composite film consisting of carbon nanotubes and a molecularly imprinted polymerized ionic liquid

The ionic liquid 1-{3-[(2-aminoethyl)amino]propyl}-3-vinylimidazole bromide was synthesized and used to fabricate a molecularly imprinted film for electrochemical sensing of myoglobin (Myo). This film was deposited on a glassy carbon electrode modified with multi-walled carbon nanotubes by using the ionic liquid as the functional monomer, Myo as the template, N,N′-methylenebisacrylamide as the crosslinker, and a redox system containing ammonium persulfate and N,N,N′,N′-tetramethylethylenediamine as the initiator. The sensing performance of the modified electrode was investigated by using the hexacyanoferrate system as an electrochemical redox probe. The results demonstrated that the sensor possesses good selectivity and high sensitivity. The oxidation peak current at the potential of ~0.3 V (vs. SCE) was found linearly related to the myoglobin concentration in the range from 60.0 nM to 6.0 μM, with a 9.7 nM detection limit at an S/N ratio of 3. The sensor was applied to the determination of Myo in spiked serum samples where it showed average recoveries (for n = 5) of 96.5 %.