New voltammetric method for determination of tyrosine in foodstuffs using an oxygen-functionalized multi-walled carbon nanotubes modified acetylene black paste electrode

In this paper, acetylene black paste electrode (ABPE) was prepared and modified by oxygen-functionalized multi walled carbon nanotubes (MWCNT-COOH). The fabricated MWCNT-COOH/ABPE was further used for the investigation on the electrochemical behavior of tyrosine by cyclic voltammetry and second-order derivative linear sweep voltammetry. In 0.1 M pH 2.6 phosphate buffer solution, a well-defined anodic peak appeared at 924 mV, which was attributed to the electrooxidation of tyrosine on the modified electrode. The electrochemical parameters of tyrosine on the modified electrode were calculated. Under the optimal conditions, the oxidation peak current of tyrosine varies linearly with its concentration in the range of 0.04-1.0 mu M, 1.0-60 mu M and 60-600 mu M, and the detection limit is 0.02 mu M. The MWCNT-COOH/ABPE was applied to the determination of tyrosine in food with satisfactory results.

Automated summary

This study prepared an acetylene black paste electrode (ABPE) modified with oxygen-functionalized multi-walled carbon nanotubes (MWCNT-COOH) for investigating the electrochemical behavior of tyrosine. The modified electrode showed a well-defined anodic peak for tyrosine oxidation, and the oxidation peak current varied linearly with tyrosine concentration. The MWCNT-COOH/ABPE was successfully applied for the determination of tyrosine in food samples.