ИСТИНА

Cardiac myoglobin is one of the earliest biomarker of acute myocardial infarction. Myoglobin can be detected by direct electron transfer reaction from electrode surface to ion Fe(III) of heme. However, this electrocatalytic reaction may be realized only by using proper immobilization matrix or nanostructuring of electrode surface. Electrochemical immunosensor based on direct detection of specific interaction between anti-myoglobin and hemoprotein and electrocatalytic properties of reduced myoglobin towards oxygen was developed. Quantitative electrochemical determination of myoglobin was performed according to the scheme: Mb–Fe(III) + ē +H+↔ Mb–Fe(II) Mb–Fe(II) + O2→ [Mb–Fe(II)O2] → Mb–Fe(III) + O2− Cathodic peak area of myoglobin Fe(III)-heme reduction was used as sensor analytical signal. Sensors consisted of screen printed electrodes, modified by gold nanoparticles in didodecyldimethylammonium bromide (DDAB) and anti-cardiac myoglobin (Figure 1). It was necessary just 1µl of plasma and about 15 min for the analysis. The developed electrochemical immunosensors can be used for express diagnostics of acute myocardial infarction. [1, 2] Plasma of healthy donors and patients with acute myocardial infarction was analyzed using electrochemical immunosensors and RAMP® immunoassay (Response Biomedical Corp). Square wave voltammetry cathodic peak of cardiac myoglobin reduction was found to be proportional to myoglobin quantity in plasma as determined by RAMP®. Figure 1. Principle circuit of developed cardio myoglobin immunosensor. 1. V. Shumyantseva, E. Suprun, T. Bulko, A. Archakov // Electroanalysis – 2009.-V.21 (3-5).-P. 530-535. 2. E. Suprun, T. Bulko, A. Lisitsa, O. Gnedenko, A. Ivanov, V. Shumyantseva, A. Archakov // Biosensors and Bioelectronics– 2010.-V.25 (7).-P. 1694–1698. This work was financially supported by the Federal Agency of Science and Innovations Ministry of Education and Science of Russian Federation (contracts № 02.512.11.2212 and 02.740.11.0306).