Quantification of zearalenone in mildewing cereal crops using an innovative photoelectrochemical aptamer sensing strategy based on ZnO-NGQDs composites

•Novel ZnO-NGQDs composites were firstly prepared by simply in-situ conjugate method.•A PEC aptasensor was innovatively developed for ZEN detection based on ZnO-NGQDs.•The PEC aptamer sensing strategy expressed high sensitivity and good selectivity.•ZEN produced among the cereal crops mildew process can be real-time monitored by the PEC aptasensor. Zearalenone (ZEN) is highly toxic to humans, and therefore, development of sensitive and effective methods for ZEN quantification in cereal crops is particularly important. Here, an innovative photoelectrochemical (PEC) aptasensor based on simply in-situ conjugated composites of zinc oxide-nitrogen doped graphene quantum dots (ZnO-NGQDs) was constructed. On addition of NGQDs, the composites displayed higher PEC signal with 8.8-fold enhancement than pure ZnO nanoparticles. A sensitive and selective PEC aptasensor was fabricated by combining the composites with ZEN aptamer, which yielded an excellent analytical performance for ZEN detection, with a wide linear range of 1.0 × 10−13–1.0 × 10−7 g mL−1 and a low detection limit of 3.3 × 10−14 g mL−1. Good recoveries were obtained using the PEC aptasensor, which were consistent with those obtained using the national standard method (HPLC-MS). Finally, ZEN in mildewing cereal crops was monitored with the PEC aptasensor, exhibiting good potential for application in cereal crops for early diagnosis.