1. Laccase-Nafion Based Biosensor for the Determination of Polyphenolic Secondary Metabolites
- Author
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Litescu, Simona, Eremia, Sandra, Bertoli, Alessandra, Pistelli, Luisa, Radu, and Gabriel, Lucian
- Subjects
Detection limit ,Chromatography ,Rosmarinic acid ,Biochemistry (medical) ,Clinical Biochemistry ,Biochemistry ,Michaelis–Menten kinetics ,Analytical Chemistry ,chemistry.chemical_compound ,chemistry ,Chlorogenic acid ,Nafion ,Electrochemistry ,Caffeic acid ,Gallic acid ,Biosensor ,Spectroscopy - Abstract
A laccase-based biosensor was developed by specific enzyme adsorption on screen-printed working electrodes of DROPSENS cells, and stabilized with Nafion 0.1% membrane. The electrode was characterized with respect to response time, sensitivity, linear range, detection limit, pH dependence, interferences, and long-term stability. The tested substrates were catechol, rosmarinic acid, caffeic acid, chlorogenic acid, and gallic acid. The optimized biosensor proved the following characteristic performances: the apparent Michaelis Menten calculated considering rosmarinic acid substrate 8.3 × 10−6 mol L−1 (r = 0.995, n = 6); the dynamic range of biosensor response for rosmarinic acid 7 × 10−7 − 1.5 × 10−6 mol L−1; the detection limit for rosmarinic acid 1.19 × 10−7 mol L−1 (RSD = 1.08%, n = 3). It was noticed that the biosensor reaches systematically 90% to 94.3% from the response obtained by LC-DAD-ESI-MS for real samples.
- Published
- 2010