Laccase Biosensor Based on Graphene-Chitosan Composite Film for Determination of Hydroquinone

Abstract

A novel laccase biosensor was fabricated by entrapping laccase in graphene-chitosan composite materials and applied to determine hydroquinone. The graphene-chitosan composite had good conductivity, high stability, and good biocompatibility. Laccase was firmly embedded into the composite without other cross-linking reagents. The morphology and electrical conductivity of graphene-chitosan film were measured by scanning electron microscopy and electrochemical impedance spectroscopy. This biosensor catalyzed the oxidation of hydroquinone to p-quinone and the reduction back to hydroquinone. The cathodic peak current of hydroquinone increased significantly with concentration in the range of 2.0 Â 10 À6 to 1.0 Â 10 À4 mol Á L À1 (r ¼ 0.9975) with a limit of detection of 2.6 Â 10 À7 mol Á L À1 . The response time of the biosensor to reach 95% of its steady-state current was less than 10 s. Moreover, the biosensor exhibited good stability, reproducibility, and selectivity.

A novel Laccase Biosensor based on Laccase immobilized Graphene-Cellulose Microfiber Composite modified Screen-Printed Carbon Electrode for Sensitive Determination of Catechol

“…However, the direct immobilization of redox active enzymes on GR surface is difficult due to its strong hydrophobic nature and the presence of only sp 2 hybridized carbon atoms28. Hence, the GR based composites have been largely used for the immobilization of laccase293031. It is reported earlier that the carbohydrate polymers and surfactants dispersed GR has been used as a potential material for immobilization of range of redox active proteins including laccase31.…”

“…Hence, the GR based composites have been largely used for the immobilization of laccase293031. It is reported earlier that the carbohydrate polymers and surfactants dispersed GR has been used as a potential material for immobilization of range of redox active proteins including laccase31. In addition, carbohydrate polymers have highly enriched with hydrophilic chemical groups on GR and result into the formation of water soluble GR hybrids32.…”

Flow injection amperometric sensor with a carbon nanotube modified screen printed electrode for determination of hydroquinone

“…7 indicated that peak height increases linearly with the hydroquinone concentration in the range of 1-50 µM, while the sensitivity was 0.3523 mV µM -1 (see inset (a)). The limit of detection (LOD) was 0.1 µM which was lower than 0.26 µM of entrapping laccase in graphene-chitosan composite materials [7] and 2 µM of laccase immobilization onto 1-aminopyrene functionalized reduced graphene oxides (rGOs)-modified glassy carbon electrode by encapsulation with chitosan [29]. 11 …”

“…In recent years, many articles reported the development of electrochemical methods for hydroquinone determination [7][8][9][10] Qu et al fabricated a novel laccase biosensor by entrapping laccase in graphene-chitosan composite materials and applied to determine hydroquinone [7]. Wu et al developed a novel photo-electrochemical sensor for determination of hydroquinone [8].…”

“…Hence, laccase biosensors directly catalyze oxidation of hydroquinone to quinone [7]. The enzyme immobilization method is necessary to develop for high stability and activity.…”