caa a22 4500 445879939 CHVBK 20180317145539.0 cr unu---uuuuu 170323e20110201xx s 000 0 eng 10.1007/s00604-010-0486-y doi (NATIONALLICENCE)springer-10.1007/s00604-010-0486-y Bienzymatic sensor based on the use of redox enzymes and chitosan-MWCNT nanocomposite. Evaluation of total phenolic content in plant extracts [Elektronische Daten] [Mirela Diaconu, Simona Litescu, Gabriel Radu] We are presenting a bienzymatic sensor for the determination of polyphenols. An ITO electrode was modified with multiwalled carbon nanotubes, and the enzymes laccase and tyrosinase were co-entrapped into a chitosan matrix. The resulting biosensor was calibrated at −50mV (vs. the Ag/AgCl reference electrode) using rosmarinic acid, caffeic acid and gallic acid as the substrates. The new biosensor resulted in a 10.7-fold increase in response sensitivity and a considerable improvement of the detection limit (42nM for rosmarinic acid). Fouling of the surface of the biosensor was prevented by applying the surfactant Tween 20. The data recorded in surfactant medium revealed a significant improvement of the operational stability and an enlarged linear concentration ranges (up to 12μM for rosmarinic acid). The sensor was used to evaluate the total phenolic content from extracts of Salvia officinalis and cultures of Basilicum callus. Figure Mechanism of polyphenols detection using ITO/Lacc-Tyr-CS-MWCNT biosensor Springer-Verlag, 2010 Laccase-tyrosinase biosensor nationallicence Dual signal amplification nationallicence Multiwall carbon nanocomposite film nanotubes nationallicence Rosmarinic acid nationallicence Total polyphenolic content nationallicence Diaconu Mirela Center of Bioanalysis, National Institute for Biological Sciences, 296, Splaiul Independentei, 060031, Bucharest, Romania aut Litescu Simona Center of Bioanalysis, National Institute for Biological Sciences, 296, Splaiul Independentei, 060031, Bucharest, Romania aut Radu Gabriel Center of Bioanalysis, National Institute for Biological Sciences, 296, Splaiul Independentei, 060031, Bucharest, Romania aut Microchimica Acta Springer Vienna 172/1-2(2011-02-01), 177-184 0026-3672 172:1-2<177 2011 172 604 https://doi.org/10.1007/s00604-010-0486-y text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s00604-010-0486-y text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Diaconu Mirela Center of Bioanalysis, National Institute for Biological Sciences, 296, Splaiul Independentei, 060031, Bucharest, Romania aut NATIONALLICENCE 700 1- Litescu Simona Center of Bioanalysis, National Institute for Biological Sciences, 296, Splaiul Independentei, 060031, Bucharest, Romania aut NATIONALLICENCE 700 1- Radu Gabriel Center of Bioanalysis, National Institute for Biological Sciences, 296, Splaiul Independentei, 060031, Bucharest, Romania aut NATIONALLICENCE 773 0- Microchimica Acta Springer Vienna 172/1-2(2011-02-01), 177-184 0026-3672 172:1-2<177 2011 172 604 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer