Electrochemical characterization of screen-printed carbonaceous electrodes for the determination of peroxidase activity in novel screen-printed flow-through modules.
A novel totally screen-printed flow-through cell for immunoanalysis is presented. It contained screen-printed carbonaceous electrodes, which allowed the determination of peroxidase activity through the electrochemical reduction of p-benzoquinone. As different electrode materials differ strongly in their electrochemical properties, electrodes resulting from various screen-printable carbonaceous pastes were characterized using the hydroquinone/ p-benzoquinone redox couple. For most of the electrodes, cyclic voltammogram peak separations of between 550 and 670 mV were observed indicating only quasi-reversible electrochemical behavior. This was confirmed by variation of the peak separation with scan rate. Heterogeneous electron transfer rates of ca. 0.5 - 1 x 10(-3) cm s(-1) and electrochemical activation energies of ca. 20 kJ mol(-1) were found. These flow-through cells were not only applied to electrochemical peroxidase activity determinations but also, in combination with a separate detector, as affinity reactors. After biotinylation of screen-printed layers, streptavidin and then biotinylated peroxidase could be bound. However, as signals were only 10-20% of those obtained with a column filled with biotinylated glass beads, only the screen-printed electrochemical detector was applied to the detection of antibodies against the African Swine Fever Virus.
Stiene
Matthias
M
German Research Centre for Biotechnology, Braunschweig.
Bilitewski
Ursula
U
D000818:Animals; D000914:Antibodies, Viral / Q000032:analysis; D016227:Benzoquinones / Q000378:metabolism; D015374:Biosensing Techniques / Q000295:instrumentation / Q000379:methods*; D019921:Biotinylation; D004563:Electrochemistry; D004566:Electrodes; D004583:Electrons; D004800:Enzymes, Immobilized / Q000032:analysis; D008855:Microscopy, Electron, Scanning; D009195:Peroxidase / Q000032:analysis* / Q000378:metabolism; D013499:Surface Properties; D013552:Swine
D000914:Antibodies, Viral; D016227:Benzoquinones; D004800:Enzymes, Immobilized; C004532:quinone; D009195:Peroxidase