Highly sensitive determination of tetracycline in chicken meat and eggs using AuNP/ MWCNT-modified glassy carbon electrodes

Glassy carbon electrodes (GCE) were modified with gold nanoparticles (AuNPs) and multi-walled carbon nanotubes (MWCNTs) by means of sputtering and electrodeposition. The electrodeposited MWCNT on gold coated GCE exhibited the optimum performance as characterized using cyclic voltammetry. The limit of detection and limit of quantitation were found to be 42 ppb and 139 ppb, respectively. The modified electrode was used as working electrode in differential pulse voltammetry to detect tetracycline (TET) residues in the eggs, wings, liver, breast, and thigh, of organic as well as non-organic chicken bought from a local supermarket. The highest concentration in the eggs, wings, liver, breast, and thigh were found to be 5.9 ppm, 2.0 ppm, 1.4 ppm, 1.3 ppm, and 1.2 ppm for organic chicken and 8.70 ppm, 4.8 ppm, 4.3 ppm, 3.3 ppm, and 2.7 ppm for the corresponding parts in non-organic chicken, respectively. The obtained concentrations were remarkably greater compared to the maximum residual limit released by the Codex Alimentarius Commission.