Related Experiment Video
Updated: Jan 21, 2026

A Generalized Method for Determining Free Soluble Phenolic Acid Composition and Antioxidant Capacity of Cereals and Legumes
Published on: June 10, 2022
Development of a highly sensitive xanthine oxidase-based biosensor for the determination of antioxidant capacity in
Magda Márcia Becker1, Eliane Braga Ribeiro2, Paulo Roberto Brasil de Oliveira Marques3
1BAE-LBBM, University of Perpignan Via Domitia, 52 Avenue Paul Alduy, 66860, Perpignan, Cedex, France; Program in Biodiversity and Biotechnology, Bionorte, Federal University of Maranhão (UFMA), Portugueses Avenue, 1966, Bacanga, 65080-805, São Luís, Maranhão, Brazil.
Abstract:
The paper describes the development of an amperometric biosensor using Prussian Blue (PB) modified electrodes containing xanthine oxidase (XOD). The enzyme is immobilized by photo-polymerization into an azide-unit pendant water-soluble photopolymer (PVA-AWP). The parameters of the fabrication of the biosensor, XOD:PVA/AWP ratio, crosslinking irradiation time, and XOD charge, were optimized. Operational conditions for electrode preparation were defined as 1:2 ratio of XOD:PVA/AWP; exposure time to neon light of 30 min; pH = 7.5 at room temperature and enzymatic charge of 8 mU per electrode. The biosensors showed stable, fast, simple, selective, cost-effective and sensitive (-2.72E-8 A mol L-1), with a good linear range (1.0-75 μmol L-1), and respectively detection and quantification limits for antioxidants of 2.17, and 7.15 μmol L-1. The applicability of this biosensor was demonstrated by in vitro analysis of gallic acid as standard antioxidant and Amazonian fruits as natural sources.
Related Concept Videos
Fruit Development, Structure, and Function
Lung Capacity
Respiratory Capacities
One key metric is the Inspiratory Capacity (IC), which represents the maximum amount of air that can be inhaled with full effort. IC is calculated by summing the tidal volume and inspiratory reserve volume, typically ranging from 2.4 to 3.6 liters.
The Functional Residual Capacity (FRC) represents the air in the...
Respiratory Volumes and Capacities
Buffers: Buffer Capacity
In the graph, pH is plotted as a function of the number of moles of base (Cb) added to a weak...
Heat Capacity: Problem-Solving
Determine the type of gas: The heat capacity of a gas depends on its molecular structure and the degree of freedom of its molecules. Different types of...

