Nanostructured voltammetric sensor for ultra-trace anabolic drugdetermination in food safety field

Abstract

tA sensitive electrochemical sensor for clenbuterol (CL) determination in bovine urine samples wasdesigned. This drug was originally developed for the treatment of respiratory pathologies. However,in the livestock industry, CL has been used as growth promoter because it stimulates the muscle growthand lipid degradation. The drug residues accumulated in animal tissues represent a potential risk forthe human health. Subsequently, the development of a fast and simple method for the CL quantificationemployed to detect its abuse in livestock production is an attractive analytical challenge.The proposed method was based on the use of a screen printed carbon electrode (SPCE) modifiedwith multiwall carbon nanotubes (MWCNTs) in a matrix of chitosan (CH) on gold nanoparticles (AuNPs)previously incorporated by electrodeposition process. The MWCNTs-CH/AuNPs/SPCE was characterizedby cyclic voltammetry, X-ray diffraction and scan electron microscopy.With the aim to carry out the CL determination, a pre-concentration procedure was required. For thispurpose, we employed anti-CL antibodies immobilized on magnetic microparticles (MPs) as bioaffinitysupport to capture the drug present in the sample. This support was exposed to a desorption process.Later, the electrochemical detection by square wave voltammetry (OSWV) was performed. The sensorexhibited excellent performances with a linear response range in concentrations from 0.01 to 6 ng mL−1.The detection and quantification limits obtained were 0.003 and 0.01 ng mL−1, respectively with an anal-ysis time of 19 min and a R.S.D. below 5.8%. As a conclusion, we can claim that the results obtained bythe proposed sensor were successful.