Laccase Carbon Paste Based Biosensors for Antioxidant Capacity. The Effect of Different Modifiers

• Published in: International journal of electrochemical science Vol. 10; no. 7; pp. 5650 - 5660
• Main Authors: Garcia, Luane Ferreira, Benjamin, Stephen Rathinaraj, Marreto, Ricardo Neves, Lopes, Flávio Marques, de Souza Golveia, Jhéssica Cavalcante, Fernandes, Neemias Cintra, Santiago, Mariângela Fontes, de Souza Gil, Eric
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.07.2015
• Subjects: antioxidant capacity; carbon paste electrode; DPV; laccase; Pycnoporus sanguineus; Pycnoporus sanguineus; DPV; carbon paste electrode; antioxidant capacity; laccase
• ISSN: 1452-3981; 1452-3981
• DOI: 10.1016/S1452-3981(23)17284-1

The natural antioxidants of food products have great influence on human health. Indeed, the protective effects against cardiovascular diseases, cancer and ageing have been attributed to their polyphenol content. In turn, the remarkable antioxidant activity of polyphenols can be easily estimated by polyphenol oxidases based biosensors. The aim of this work was check the effect of modifiers on the improvement of biosensors concerning to performance, in order to express the antioxidant activity and total polyphenol content of complex natural samples such as coffee beverages. The biosensors were constructed by occlusion of crude extract of Pycnoporus sanguineus containing laccase, in different carbon paste based composites. The electrochemical properties of the resulting composites, namely Carbon Paste-Laccase (CPL), CPL modified with Glutaraldeide (CPL-Glu), Bovine Serum Albumin (CPL-BSA), Chitosan (CPL-Ch), Silica (CPL-SiO), Titanium dioxide (CPL-TiO), DNA (CPL-DNA), Carbon Nanotubes (CPL-CN), non-activated Carbon Nanotubes (CPL-nCN) and activated Carbon Nanotubes plus DNA (CPL-DNA:CN) were evaluated by voltammetry in different experimental conditions. In order, the effect of electrolyte composition, pH, scan rate, pulse amplitude, response time and concentration range were carefully evaluated, whereas rutin and/or cathecol were employed as standard solutions. The highest sensitivity level and lowest detection limit were obtained for CPL-DNA:CN. In addition, the biosensor demonstrated suitable stability over 10 days and good repeatability (RSD < 5%). CPL-DNA:CN was used for the determination of total phenol content of coffee samples, expressed as Gallic Acid equivalents (GAEq) and the results were compared with those from the DPPH and Folin–Ciocalteu spectrophotometric methods. Further, the inherent sensitivity of electroanalytical methods, the amperometric biosensor exhibits some interesting advantages such as simplicity due to the minimal sample preparation and leading to rapidity of antioxidant capacity assay.