▎ 摘　　要

In this work, an electrochemical immunosensor to determine patulin mycotoxin in apple juice is developed. It consists of a glassy carbon electrode modified with a dispersion of graphene oxide and polyclonal anti-patulin antibodies bound to their oxygenated groups. Patulin determination was performed by electrochemical impedance spectroscopy. The calibration curve is linear for a concentration range from 1 x 10(-2) to 10 ng mL(-1). The limit of detection and the concentration of patulin to obtain 50% inhibition (IC50) were 9.8 pg mL(-1) and 360 pg mL(-1), respectively. In addition, an acceptable accuracy, with a percentage coefficient of variation (%CV) close to 20%, and recovery percentage (%R) of 86% were found. The electrochemical immunosensor has the advantage of allowing the determination of patulin without any pre-treatment of the samples. The results obtained from the electroanalytical technique were compared with those obtained by HPLC.