Determination of Tyrosine in the Presence of Sodium Dodecyl Sulfate Using a Gold Nanoparticle Modified Carbon Paste Electrode

Abstract

A carbon paste electrode modified with gold nanoparticles (AuMCPE) was used as a highly sensitive sensor for determination of Tyrosine (Tyr), in the presence of an anionic surfactant, sodium dodecyl sulfate (SDS), in aqueous solution. The measurements were carried out by using of differential pulse voltammetry (DPV), cyclic voltammetry (CV), amd chronocoulometry and chronoamperometry methods. The prepared electrode shows voltammetric responses with high sensitivity and selectivity for Tyr in the presence of SDS. The relationship between the oxidation peak current of Tyr and its concentration was obtained linearly and it was 1.0 × 10⁻⁷ to 1.0 × 10⁻⁵ M with a detection limit of 5.5 × 10⁻⁸ M in the absence of SDS. On the other hand the oxidation peak current of Tyr increased significantly at AuMCPE in the presence of SDS and its detection limit was reduced to 2.7 × 10⁻⁹ M. The proposed voltammetric approach was also applied to the determination of Tyr concentration in human serum.

Keywords:

• Carbon paste modified electrode
• Gold nanoparticle
• Sodium dodecyl sulfate
• Tyrosine
• Voltammetry

Acknowledgments

The authors are grateful to the University of Kashan for supporting this work by Grant No.15919514.