Magneto-controlled aptasensor for simultaneous detection of ochratoxin A and fumonisin B1 using inductively coupled plasma mass spectrometry with multiple metal nanoparticles as element labels.

The simultaneous detection of multiple mycotoxins is important for food safety. Here, a magneto-controlled aptasensor for quantitative analysis of ochratoxin A (OTA) and fumonisin B1 (FB1) using inductively coupled plasma mass spectrometry (ICP-MS) with multiple metal nanoparticles as element labels was proposed. Firstly, the OTA aptamer (Apt1) and the FB1 aptamer (Apt2) immobilized on the magnetic beads (MBs) were hybridized with probe DNA1-CdSe quantum dots (pDNA1-QDs) and probe DNA2-Ag nanoparticles (pDNA2-Ag NPs) labels, producing the MBs-Apt1-pDNA1-QDs and MBs-Apt2-pDNA2-Ag NPs conjugates, respectively. Then, the MBs-Apt1-OTA and MBs-Apt2-FB1 conjugates were generated with the addition of targets, resulting the pDNA1-QDs and pDNA2-Ag NPs labels released into the solutions. Finally, the signal intensities of 111Cd and 107Ag were detected by ICP-MS, achieving limits of detection of 0.10 and 0.30 ng mL-1 for OTA and FB1, respectively. The assay showed high specificity and succeeded in wheat flour. The method provides an ideal model for sensitive analysis of multiple mycotoxins in food samples.