Sensitive and Facile Electrochemiluminescent Immunoassay for Detecting Genetically Modified Rapeseed Based on Novel Carbon Nanoparticles

A highly sensitive electrochemiluminescent (ECL) immunoassay targeting PAT/bar protein was facilely developed for genetically modified (GM) rapeseed detection using carbon nanoparticles (CNPs) originally prepared from printer toner. In this work, CNPs linked with antibody for PAT/bar protein were used to modify a working electrode. After an immunoreaction between the PAT/bar protein and its antibody, the immunocomplex formed on the electrode receptor region resulted in an inhibition of electron transfer between the electrode surface and the ECL substance, thus led to a decrease of ECL response. Under the optimal conditions, the ECL responses linearly decreased as the increase of the PAT/bar protein concentration and the GM rapeseed RF3 content in the ranges of 0.10–10 ng/mL and 0.050–1.0%, with the limits of detection of 0.050 ng/mL and 0.020% (S/N = 3). These results open a facile, sensitive, and rapid approach for the safety control of agricultural GM rape.