A comparison of three amperometric phenoloxidase–Sonogel–Carbon based biosensors for determination of polyphenols in beers

Nanofibrous membrane based tyrosinase-biosensor for the detection of phenolic compounds

“…Regarding pyrocatechol, this result confirmed what reported in literature [22]. But, relatively to the other two substances, other tyrosinase biosensors [13] showed a higher sensitivity for epicatechin than caffeic acid, contrarily to our results. This suggested again that nylon nanofibrous membrane may influence tyrosinase-biosensor selectivity.…”

“…A large number of amperometric biosensors for the determination of phenolic compounds have been developed [8][9][10]. Most of them are based on the immobilization of tyrosinase on different electrode supports [11][12][13][14].…”

Estimation of beer stability by sulphur dioxide and polyphenol determination. Evaluation of a Laccase-Sonogel-Carbon biosensor

“…The Sonogel-Carbon biosensors based on laccase were fabricated as follows (ElKaoutit et al, 2008): an adequate quantity of enzyme in order to obtain an acceptable number of units of enzyme per electrode was dissolved in 30 lL of acetate buffer, 0.2 mol L À1 pH 5. Afterwards, 1.25 lL of glutaraldehyde was added and the mixture was immersed in ultrasonic bath for 3 min, and then modified by adding 3.5 lL of Nafion.…”

“…The methods used in this work are: the spectrophotometric p-rosaniline for sulphur dioxide determination, the spectrophotometric Folin-Ciocalteú s for reducing capacity, the spectrophotometric ABTS Å+ simulation for the antioxidant capacity and the evaluation of an amperometric biosensor previously developed by some of us for polyphenols determination (ElKaoutit et al, 2008).…”

State of the Art in the Field of Electronic and Bioelectronic Tongues – Towards the Analysis of Wines

“…The decrease of hydrogen peroxide was monitored; it corresponded to the oxidized amount of phenolic compounds in wine and tea [135]. Co-immobilization of laccase and tyrosinase on the Sonogel-Carbon electrode using glutaraldehyde as a crosslinker and Nafion-ion exchanger as a protective additive provided the biosensor which summed the responses of both enzymes to five individual polyphenols and estimated the total phenol index in the beer samples with high correlation factor of 0.99 in comparison with the Folin-Ciocalteau reagent [138].…”