1. An oxygen-insensitive amperometric galactose biosensor based on galactose oxidase co-immobilized with an Os-complex modified redox polymer.
- Author
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Figueiredo, Carina, García-Ortega, Andrea, Mandal, Tanushree, Lielpetere, Anna, Cervantes, Fadia, Demurtas, Denise, Magner, Edmond, Plou, Francisco J., Schuhmann, Wolfgang, Leech, Donal, Pita, Marcos, and De Lacey, Antonio L.
- Subjects
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REDOX polymers , *YOGURT , *GALACTOSE , *CARBON electrodes , *BIOSENSORS , *CHARGE exchange , *REDUCTION potential - Abstract
Monitoring galactose levels in dairy products can help to prevent severe complications with a hereditary metabolic disease such as galactosemia, a life-threatening disease. The current state of the art requires the development of less expensive, more reliable and specific methods to determine galactose levels in food in a practical way. We report the development and optimization of an amperometric biosensor for determination of galactose in dairy products based on galactose oxidase (GaOx) co-immobilized with an osmium-complex modified redox polymer on glassy carbon electrodes. To attain the maximum catalytic currents based on mediated electron transfer, two Os-complex based polymers with different redox potentials and different enzyme:redox polymer ratios were studied. The optimized GaOx-modified electrode gave a maximum electrocatalytic response of galactose oxidation that was not affected by the presence of O 2 , indicating fast wiring of the enzyme by the Os-complex modified redox polymer. The biosensor that gave the best analytical parameters for galactose detection was further tested for measuring galactose concentration in lactose-containing and lactose-free milk and yogurt samples under aerobic conditions. The results obtained with the amperometric biosensor were validated by high-performance anion-exchange chromatography coupled with pulsed amperometric detection (HPAEC-PAD). [ABSTRACT FROM AUTHOR]
- Published
- 2023
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