A novel combined thermometric and amperometric biosensor for lactose determination based on immobilised cellobiose dehydrogenase

摘要: A novel method for lactose determination in milk is proposed. It based on oxidation of by cellobiose dehydrogenase (CDH) from the basidiomycete Phanerochaete chrysosporium, immobilised an enzyme reactor. The reactor was prepared cross-linking CDH onto aminopropyl-silanised controlled pore glass (CPG) beads using glutaraldehyde. combined biosensor worked flow injection analysis (FIA) mode and developed simultaneous monitoring thermometric signal associated with enzymatic p-benzoquinone as electron acceptor electrochemically generated current hydroquinone formed. highly reproducible linear response obtained between 0.05mM 30mM. For a set more than 500 samples R.S.D. less 10% achieved. assay time ca. 2min per sample. sensor applied dairy (milk fat content 1.5% or 3% also "lactose free" milk). No sample preparation except dilution buffer needed. proposed rapid, suitable repeated use allows possibility to compare results two different detection methods, thus providing built-in quality assurance. Some differences observed methods indicate that dual approach can be useful mechanistic studies redox enzymes. In addition, system opens up interesting possibilities properties mechanisms. (Less)