Sensitive electrochemical immunosensor using a bienzymatic system consisting of β-galactosidase and glucose dehydrogenase.

摘要: Bienzymatic systems are often used with electrochemical affinity biosensors to achieve high signal levels and/or low background levels. It is important select two enzymes whose reactions do not exhibit mutual interference but have similar optimal conditions. Here, we report a sensitive immunosensor based on bienzymatic system consisting of β-galactosidase (Gal, hydrolase enzyme) and flavin adenine dinucleotide-dependent glucose dehydrogenase (FAD-GDH, redox enzyme). Both showed activities at neutral pH, the catalyzed by them did interference, electrochemical-enzymatic cycling FAD-GDH coupled enzymatic amplification Gal enabled amplification. Among three amino-hydroxy-naphthalenes 4-aminophenol (potential products), 4-amino-1-naphthol highest Glucose, as an electro-inactive, stable reducing agent for cycling, helped in achieving Our could detect parathyroid hormone detection limit ∼0.2 pg mL−1, implying that it can be highly other biomarkers human serum.