8/2013-14 Sensing in Electroanalysis

Permanentní URI k tomuto záznamuhttps://hdl.handle.net/10195/56677

Procházet

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Otevřený přístup
Development of a laccase biosensor for determination of Phenolic micropollutants in surface waters
(Univerzita Pardubice, 2014) Souza Gil, Eric de; Rezende, Stefani Garcia; Júnior, Eli José Miranda Ribeiro; Barcelos, Hernane Toledo; Scalize, Paulo Sérgio; Santiago, Mariangela Fontes; Quintino, Michelle Pereira; Somerset, Vernon Sydwill
Laccase is a poliphenoloxidase enzyme that catalyzes the oxidation of phenolic compounds in the corresponding quinones. The current obtained in this redox process can be used for quantitative analysis. In this work, a carbon paste biosensor modified gluteraldehyde functionalized silica and an enzymatic extract of the Pycnoporus sanguineus fungi as a lacase source is proposed for phenol determination. The effect of carbon paste and electrolyte composition, pH from 3.0 to 8.0, start potential from 0.55 to 0.25 mV, scan rate from 5 to 25 mV s-1 and potential pulse amplitude from 10 to 60 mV on the differential pulse voltammetric response was investigated. A linear correlation of r² = 0.9946 was obtained for the phenol content (catechol) in the concentration range from 50 to 500 nmol L-1, with a detection limit of 30 nmol L-1. This biosensor was used for the determination of different kinds of phenolic compounds, presenting a better response for catechol.
Otevřený přístup
On the performance of amperometric tyrosinase carbon paste biosensor in the presence of catechol, resorcinol, or hydroquinone
(Univerzita Pardubice, 2014) Sýs, Milan; Metelka, Radovan; Vytřas, Karel
This study was aimed to understand which substitution position of hydroxy groups on benzene ring is the most suitable for active site of enzyme tyrosinase, and also to determine if tyrosinase is a useful biological component for the development a biosensor based on carbon material for the determination of polyphenolic compounds in food samples. Electrochemical properties of diphenols (catechol, resorcinol, and hydroquinone) at bare carbon paste electrode (CPE) and CPE surface-modified with conductive copolymer Nafion and enzyme mushroom tyrosinase (CPE/Tyr/Nafion) were investigated using cyclic voltammetry and hydrodynamic amperometry.