Electrochemical immunosensing using a mesonanostructured functional platform for determination of a potent anabolic in bovine urine samples

G.A. MESSINA; J. RABA; P. ARANDA; F.A. BERTOLINO,; C. MOREIRA; S.V. PEREIRA

Congreso; 28th Anniversary World Congress on Biosensors; 2018

Anabolic steroids are commonly used in human and animal therapy because they improve the protein synthesis and body mass growth. However, the abuse of anabolic steroids in the past decade led to frequent detection of these compounds in doping analysis. Stanozolol (STA) belongs to the exogenous androgenic/anabolic steroids category and is allowed for zootechnical use. However, STA is banned for fattening purpose for animals, intended for human consumption.For this reason, our work describes the preparation of an immunosensor for electrochemical detection of STA in bovine urine samples. The sensing procedure is based on a nanostructured functional platform composed of gold nanoparticles electrosynthesized on a screen-printed carbon electrode (SPCE) modified with ordered mesoporous carbon.A nanostructured mesoporous carbon CMK-3 type was successfully obtained from ordered mesoporous silica SBA-15 type used as hard-templated and sucrose as carbon precursor. Due to its high specific surface area (1125 m2 g-1), large pore volume (1.16 cm3 g-1), uniform mesostructure (4.4 nm), good conductivity and excellent electrochemical activity, this porous carbon material provides an adequate sensitivity for the electrochemical determination.The electrosynthesis of gold nanoparticles allowed enlarges the surface for immobilization of anti-STA antibodies. The nanocomposite film was characterized by scanning electron microscopy, energy dispersive X-ray spectroscopy and cyclic voltammetry. The analytical curve showed a linear response range for detecting STA in concentrations from 0 to 100 ng mL-1 with a limit of detection of 0.031 ng mL-1. The analysis time was 12 min against the 90 min that takes the enzyme immunoassay method. To conclude, the proposed method exhibited a good selectivity, stability and reproducibility for immunosensing of growth promoter in the livestock production.