Polymer matrices with molecular memory as affine adsorbents for the determination of myoglobin as a cardiac marker of acute myocardial infarction by voltammetry

A possibility of myoglobin determination using screen-printed graphite electrodes modified with a poly( o -phenylenediamine)-based molecularly imprinted polymer ( MIP ) obtained by the electropolymerization of o -phenylenediamine monomer molecules on the surface of a screen-printed graphite electrode in the presence of myoglobin template molecules is considered. It is shown that the conjugation of MIP with multiwall carbon nanotubes ( MWCNT ) results in an increase in the sensitivity of the MIP-biosensor in the electrochemical determination of myoglobin by the direct registration of the reduction peak of hemoprotein Fe 3+ by square wave voltammetry on screen-printed graphite electrodes modified with MWCNT/MIP and MIP. Equilibrium dissociation constants K d for the interaction of myoglobin with MWCNT/MIP- and MIP-electrodes, which equaled (9.8 ± 2.6) × 10 –11 and (2.4 ± 0.5) × 10 –8 M, respectively, are calculated. It is shown that the sensitivity of the electrochemical MWCNT/MIP-biosensor for myoglobin determination (1.5 × 10 –2 A/nmol of myoglobin) is higher than that of the MIP-biosensor (2.0 × 10 –4 A/nmol of myoglobin).