Design of a biosensor based on 1-(4-nitrophenyl)-2,5-di(2-thienyl)-1H pyrrole

Tuncagil S., Varis S., TOPPARE L. K.

JOURNAL OF MOLECULAR CATALYSIS B-ENZYMATIC, vol.64, pp.195-199, 2010 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 64
  • Publication Date: 2010
  • Doi Number: 10.1016/j.molcatb.2009.06.002
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.195-199
  • Keywords: Conducting polymers, Electrochemical biosensors, Enzyme immobilization, Catechol, L-Tyrosine, Tyrosinase, CONDUCTING POLYMER, POLYPHENOL OXIDASE, PHENOLIC-COMPOUNDS, IMMOBILIZATION, TYROSINASE, ELECTRODE, COPOLYMERS, ENZYMES
  • Middle East Technical University Affiliated: Yes


Immobilization of polyphenol oxidase (tyrosinase, E.C. was achieved on a copolymer of 1-(4-nitrophenyl)-2,5-di(2-thieny1)-1H-pyrrole [SNS(NO2)] with pyrrole USNS(NO2)]/PPy) via electrochemical polymerization. Two different substrates; catechol and L-tyrosine were used for the characterization of biosensor. The kinetic parameters of the biosensor, maximum reaction rate of the enzyme (V-max) and Michaelis-Menten constant (K-m) were determined for two different substrates. V-max was found as 0.02 mu mol/min electrode for both substrates. K-m values were determined as 250 and 2 mM for catechol and L-tyrosine respectively. Calibration curves for enzyme activity versus substrate concentration were plotted between 0.05 and 0.5 M catechol and between 0.8 and 2.5 mM L-tyrosine. Optimum temperature and pH, operational and storage stabilities of immobilized enzyme were examined. (C) 2009 Elsevier B.V. All rights reserved,