A simple electrochemical immunosensor for sensitive detection of transgenic soybean protein CP4-EPSPS in seeds

Soybean is the most produced crop in Argentina, and 99 % corresponds to genetically modified soybean. One of the main produced varieties is Roundup Ready® soybean (RR), which was modified to express the enzyme CP4 5-enolpyruvylshikimate 3-phosphate synthase (CP4 EPSPS), which confers resistance to glyphosate, the main herbicide worldwide used. The possible impact of genetically modified organisms (GMO) has generated public concerns, thus increasing interest in the development of GMOs detection devices. In this work, an electrochemical immunosensor for CP4 EPSPS detection in soybean seeds was obtained, by using a gold electrode modified with an anti-CP4 EPSPS polyclonal antibody produced in our laboratory. The presented immunosensor resulted in a simple, low-cost, fast, and reproducible device. Also, labeling and/or signal amplification system was not necessary, since the sensor showed high sensibility with a low detection limit (lower at 0,038 % RR soybean, 38 ng mL^-1 CP4 EPSPS).