Preparation And Applications Of Three New Types Of Chemically Modified Electrodes

The application of new material for the preparation of selective and sensitive modified electrodes is one of the active areas. In this thesis, chemically modified electrodes using MHCF and C₆₀-based materials were fabricated. This study may broaden the application range of MHCF and C₆₀-based materials and enrich the content of electroanalytical chemistry. There are three chapters in this thesis. The main contributes of author are summarized as follows:A SnHCF modified carbon ceramic electrode (SnHCF/CCE) was prepared by electrodeposition. The electrochemical behaviors and electrocatalytic properties for SO₃^2- oxidation were investigated by electrochemical methods. Studies showed that the modified electrode exhibited a pair of well-defined redox peak with the formal potential of +0.701 V, ascribing to the redox of SnHCF, was obtained. The SnHCF/CCE showed good electrocatalytical ability for SO₃^2- oxidation and the relationship between peak current and SO₃^2- concentration was linear in the range of 8.0×10^-6 - 4.0×10^-4 mol·L^-1 (R = 0.9989), The sensitivity and detection limit was 14.9μA·(mmol·L^-1)^-1 and 3×10^-6 mol·L^-1, respectively. Moreover, the SnHCF/CCE can be used for SO₃^2- determination in vinegar and liqueur samples and a satisfictional results was obtained.A pyrocatechol violate/C₆₀ modified glassy carbon electrode (PCV/C₆₀/GCE) was prepared by adsorption method. The electrochemical behaviors and electrocatalytic properties of the modified electrode were investigated by electrochemical methods. Studies showed that the modified electrode exhibited a pair of well-defined redox peak with the formal potential of +0.28 V, ascribing to the redox process of quinine-hydroquinone functionalities in PCV. The PCV/C₆₀/GCE showed good electrocatalytical ability for H₂O₂ reduction and the relationship between peak current and H₂O₂ concentration was linear in the range of 2.9×10 ^-6 - 2.6×10^-4 mol·L^-1 (R = 0.9994), The sensitivity and detection limit was 1.3μA·(mmol·L^-1)^-1 and 2×10^-6 mol·L^-1, respectively.A C₆₀-thionine modified Au electrode (C₆₀-Th/Au) and a glucose oxidase/thionine-C₆₀ modified Au electrode (GOD/C₆₀-Th/Au) were prepared. The electrochemical behaviors and electrocatalytic properties of the modified electrode were investigated by electrochemical methods. Studies showed that the modified electrode exhibited a pair of well-defined redox peak with the formal potential of-0.19 V, ascribing to the redox process of Th/Th⁺ redox couples. The C₆₀-Th/Au showed good electrocatalytical ability for H₂O₂ reduction and the relationship between peak current and H₂O₂ concentration was linear in the range of 5.8×10^-6 - 3.9×10^-4 mol·L^-1 (R = 0.9999), The sensitivity and detection limit was 2.8μA·(mol·L^-1)^-1 and 3×10^-6mol·L^-1, respectively.