화학공학소재연구정보센터
Journal of the Electrochemical Society, Vol.166, No.6, B472-B481, 2019
Studies on the Development of Electrochemical Immunosensor for Detection of Diphtheria Toxoid
In the recent years, the growing number of diphtheria cases (also lethal) has been observed. As the diphtheria disease characterizes with rapid development and highly nonspecific initial symptoms, the fast detection method of pathogenic Corynebacterium strains, especially by the diphtheria toxin, is of particular importance. Herein, we present the studies on the development of an electrochemical immunosensor toward diphtheria toxoid (part of the vaccines inducing an immune response). The monoclonal (from rat ascites) and polyclonal (guinea pigs) antibodies were compared as receptor elements. The influence of different immobilization methods, electrode surface blocking agents or metallic nanoparticles on the biosensor response was examined. The degree of surface modification and further interaction with diphtheria toxoid was verified using cyclic and square - wave voltammetry as well as impedance spectroscopy. The calculated dissociation constant (6.892.10(-5) Lf/mL) for the developed sensing layer confirmed high affinity toward the toxoid. The linear dependence of redox current change versus diphtheria toxoid was recorded within 10(-4) to 10(-1) Lf/mL. Moreover, the selectivity studies indicated a distinctly lower biosensor response for thrombin, lysozyme, IgG and Phe-Ala peptide what allowed for detection of diphtheria toxoid in real sample. (C) 2019 The Electrochemical Society.