Copper nanoparticles applied to the preconcentration and electrochemical determination of β-adrenergic agonist: An efficient tool for the control of meat production

Abstract

A novel method for preconcentration and electrochemical detection of zinterol in bovine urine samples was developed. In order to improve the limit of detection, the surface of a screen-printed carbon electrode was modified with electrodeposited metal copper nanoparticles. The experimental electrodeposition optimization was performed using a central composite design (CCD), involving precursor concentration, potential and time applied. We used mesoporous shuttle like oxide copper nanoparticles for the preconcentration step to avoid interferences with many compounds present in the sample matrix. The optimal working condition for the preconcentration step was performed using a two-level fractional factorial design. Then, a final optimization of the significant factors was carried out using a CCD. The obtained enhancement factor for a sample volume of 30 mL was 35 fold. The calibration curve showed a linear range between 0.5-45 ng mL-1 and the limit of detection was 0.016 ng mL-1. The intra- and inter-assay coefficients of variability were below 4% and 5%, respectively. Copper nanoparticles were characterized by transmission electron microscopy, cyclic voltammetry and energy dispersive X-ray spectroscopy.