A highly sensitive and automated method for the determination of hypoxanthine based on lab-on-valve approach using Fe3O4/MWCNTs/β-CD modified electrode

A Fe3O4/multiwall carbon nanotubes/β-cyclodextrin (Fe3O4/MWCNTs/β-CD) modified electrode, for highly sensitive and automated hypoxanthine measurements, was developed in a sequential injection lab-on-valve system. The electrochemical oxidation behavior of hypoxanthine was investigated in phosphate buffer solution by cyclic voltammetry and linear sweep voltammetry. The Fe3O4/MWCNTs/β-CD modified electrode exhibits preferably analytical characteristics in electrocatalytic activity towards the oxidation of hypoxanthine. Under optimized conditions, the log oxidation peak current intensity was proportional to log hypoxanthine concentration covering the range from 5.0×10−8 to 1.0×10−5 mol L−1 with a correlation coefficient of 0.9965. A detection limit of 0.3×10–8 mol L−1 was achieved along with a sampling frequency of 20 h−1. This hyphenated system offers some advantages in terms of rapidness, sensitivity and ease of manipulation. Its further applications were utilized for the determination of hypoxanthine in meat samples.