Biotin ligands labeled with daunomycin as an electrochemical probe for avidin and biotin interaction.

摘要

Electroactive biotin ligands were prepared by the reaction of daunomycin with biotinylating reagents with a different spacer. These biotin ligands exhibited similar electrochemical properties to those of daunomycin, but the adsorptivity of the ligands on the electrode increased with increasing length of the spacer. The electrode response of these ligands decreased when specifically bound with avidin. This made it possible to detect electroinactive avidin indirectly. Biotin was detected by observingthe competitive reaction between biotin and the ligands for the limited binding sites of avidin. The binding strength of the labelled biotins with avidin was compared with that of unlabelled biotin by using an enzyme assay.