Sensitive voltammetric and amperometric responses of respiratory toxins at hemin-adsorbed carbon-felt  

作　　者：Yasushi Hasebe Yue Wang 

机构地区：[1]Department of Life Science and Green Chemistry,Faculty of Engineering,Saitama Institute of Technology [2]School of Chemical Engineering,University of Science and Technology Liaoning

出　　处：《Journal of Environmental Sciences》2013年第6期1055-1062,共8页环境科学学报（英文版）

基　　金：supported in part by the NEXT-supported Program for the Strategic Research Foundationat Private Universities,2011-2015

摘　　要：A hemin [iron-Fe（III） protoporphyrin IX chloride] was adsorbed onto a carbon-felt （CF）, which is a microelectrode ensemble of micro carbon fiber （ca. 7 ~tm diameter）. The resulting hemin-adsorbed-CF （hemin-CF） showed a well-defined redox wave based on the hemin- Fe（III）/Fe（II） redox process with the formal potential of -0.225 V vs. Ag/AgC1 in deoxygenated phosphate]citrate buffer solution （0.1 mol/L, pH 5.0）. The apparent heterogenous electron transfer rate constant was estimated to be 8.6 sec-1. In air-saturated electrolyte solution, the hemin-CF exhibited an excellent electrocatalytic activity for the reduction of dioxygen （O2）. This activity was reversibly inhibited by respiratory toxins such as cyanide and azide, which bind sixth coordination position of iron active center of hemin. The electrocatalytic Oz reduction current at the hemin-CF was modulated by the toxins in a concentration-depending manner. Based on the relationship between the %inhibition and the toxin concentration, apparent inhibition constants of cyanide and azide were evaluated to be 4.52 and 1.98 Ixmol/L, respectively. When the hemin-CF was used as a working electrode unit of the CF-based electrochemical flow-through detector with air-saturated carrier, the injection of the azide induced peak-shape current responses, which allowed rapid and continuous flow-amperometric determination of azide with high sensitivity.A hemin [iron-Fe（III） protoporphyrin IX chloride] was adsorbed onto a carbon-felt （CF）, which is a microelectrode ensemble of micro carbon fiber （ca. 7 ~tm diameter）. The resulting hemin-adsorbed-CF （hemin-CF） showed a well-defined redox wave based on the hemin- Fe（III）/Fe（II） redox process with the formal potential of -0.225 V vs. Ag/AgC1 in deoxygenated phosphate]citrate buffer solution （0.1 mol/L, pH 5.0）. The apparent heterogenous electron transfer rate constant was estimated to be 8.6 sec-1. In air-saturated electrolyte solution, the hemin-CF exhibited an excellent electrocatalytic activity for the reduction of dioxygen （O2）. This activity was reversibly inhibited by respiratory toxins such as cyanide and azide, which bind sixth coordination position of iron active center of hemin. The electrocatalytic Oz reduction current at the hemin-CF was modulated by the toxins in a concentration-depending manner. Based on the relationship between the %inhibition and the toxin concentration, apparent inhibition constants of cyanide and azide were evaluated to be 4.52 and 1.98 Ixmol/L, respectively. When the hemin-CF was used as a working electrode unit of the CF-based electrochemical flow-through detector with air-saturated carrier, the injection of the azide induced peak-shape current responses, which allowed rapid and continuous flow-amperometric determination of azide with high sensitivity.

关 键 词：respiratory toxin hemin carbon-felt cyanide azide voltammetry AMPEROMETRY 

分 类 号：X171.5[环境科学与工程—环境科学]