The diploma thesis presents the results of the studies of thin layer film composed of N,N',N'',N'''-tetramethyl-tetra-3,4-pyridinoporphyrazinocobalt. This film is deposited on the surface of highly oriented pyrolytic graphite. The modified electrode displayed electrocatalytic activity to oxidation of sulphide anions and cysteine. It has been studied the possibility of enhancement of stability of the immobilized film by the nafion. This electrode was used for the analytical determination of sulphide anions and cysteine. Keywords: highly oriented pyrolytic graphite, porphyrazines, hydrogen sulphide, cysteine, nafion, cyclic voltammetry, atomic force microscop
