An electrochemical sensor for the determination of tartrazine based on CHIT/GO/MWCNTs/AuNPs composite film modified glassy carbon electrode

Abstract

A novel nanocomposite film of chitosan/graphene oxide (CHIT/GO)/multi-walled carbon nanotubes (MWCNTs)/gold nanoparticles (AuNPs) was applied to fabricate glassy carbon electrode (CHIT/GO/MWCNTs/AuNPs/GCE) for the determination of Tartrazine (TZ), synthetic dyes in food products. The electrochemical sensors found it to be highly sensitive by combining the signal amplification properties of GO and the excellent electronic and antifouling properties of MWCNTs. The CHIT/GO/MWCNTs/AuNPs/GCE exhibited as superior electron transfer materials and possesses intercalation properties which provide synergistic influence on the increment of the current signals. The optimum conditions were found at pH 7, 30 s, and 0.3 Vs^-1. The modified GCE obtained with a linear response ranging from 10 to 100 mg mL^-1 (r² = 0.99037) with a sensitivity of 0.018 μA μM^-1. The limit of detection (LOD) and quantification obtained were 1.45 and 4.83 mg mL^-1, respectively. The determination of TZ in spiked samples was reliable with recovery percentage from 94.52 to 109.0%. The developed sensor successfully tested in the determination of TZ analyte in commercial candy, jelly, and soft drinks with acceptable results.

Keywords: Tartrazine; electrochemical sensor; food colorants; gold nanoparticles; graphene; multi-walled carbon nanotube.