Immobilised tyrosinase-based biosensor for the detection of tea polyphenols

Abstract

An amperometric principle-based biosensor containing immobilized enzyme tyrosinase has been used for detection of polyphenols in tea. The immobilized tyrosinase-based biosensor could detect tea polyphenols in the concentration range 10-80 mmol L(-1). Immobilization of the enzyme by the crosslinking method gave good stable response to tea polyphenols. The biosensor response reached the steady state within 5 min. The voltage response was found to have a direct linear relationship with the concentration of polyphenols in black tea samples. Enzyme membrane fouling was observed with number of analyses with a single immobilised enzyme membrane. The tyrosinase-based biosensor gave maximum response to tea polyphenols at 30 degrees C. The optimum pH was 7.0. This biosensor system can be applied for analysis of tea polyphenols. Variation in the biosensor response to black tea infusions gave an indication of the different amounts of theaflavins in the samples, which is an important parameter in evaluating tea quality. A comparative study of the quality attributes of a variety of commercially available brands of tea were performed using the biosensor and conventional analytical techniques such as spectrophotometry.

Novel Coulometric Approach to Evaluation of Total Free Polyphenols in Tea and Coffee Beverages in Presence of Milk Proteins

“…Amperometric laccase-based biosensors for the determination of polyphenols in wines (Gomes and Rebelo 2003;Fernandes and Rebelo 2009) and plant extracts are described (Diaconu et al 2010). Biosensor containing enzyme tyrosinase immobilized by the crosslinking method has been used for detection of polyphenols in tea (Abhijith et al 2007). Biosensor based on the biimmobilization of laccase and tyrosinase phenoloxidase enzymes and the Sonogel-Carbon as electrochemical transducer has been developed for estimation of the total polyphenol index in beer samples (ElKaoutit et al 2007).…”

Adsorptive Stripping Voltammetric Detection of Tea Polyphenols at Multiwalled Carbon Nanotubes‐Chitosan Composite Electrode

“…In previous reports, the electrochemical detection of TPs was limited to the single component of tea polyphenols separated by HPLC, and the working electrode was without modification. Recently, Abhijith and co-workers [28] reported the detection of TPs with linear range of 10 -80 mM by using tyrosinase-based biosensor. More recently, Comptons group [29] reported the electrochemical sensing of epigallocatechin gallate and epigallocatechin based on the redox reaction of aminophenol/quinoneimine.…”

Isolation, Cloning and Characterization of a Tyrosinase with Improved Activity in Organic Solvents from <i>Bacillus megaterium</i>

“…Chen et al [2002] reported the novel use of tyrosinase for the in vitro conjugation of the protein gelatin to the polysaccharide chitosan. Finally, biosensors based on tyrosinases were designed for measuring phenols, polyphenols and pesticides [Abhijith et al, 2007; Tanimoto de Albuquerque and Ferreira, 2007].…”