A dual-colored persistent luminescence nanosensor for simultaneous and autofluorescence-free determination of aflatoxin B1 and zearalenone

Mycotoxins contamination in agricultural products poses a serious threat to human and animal health, so rapid and sensitive nanosensors for simultaneous determination of multiple mycotoxins in food samples are highly desirable for food safety monitoring. Herein, we report the fabrication of functional dual-colored persistent luminescence nanoparticles (PLNPs) in conjunction with Fe3O4 magnetic nanoparticles as a nanosensor for the simultaneous biosensing of aflatoxin B-1 (AFB(1)) and zearalenone (ZEN) in food samples. Two types of PLNPs with a single excitation wavelength, Zn2GeO4:Mn2+ and Zn1.25Ga1.5Ge0.25O4:Cr3+,Yb3+,Er3+, are employed as the signal units, and aptamers with high affinity and specificity to the corresponding mycotoxins are used as the recognition units. The nanosensor was fabricated by hybridizing the aptamer modified PLNPs with the complementary DNA modified Fe3O4. The developed nanosensor offers the integrated merits of autofluorescence-free detection of persistent luminescence, the high specificity of aptamer and the high speed of magnetic separation, allowing highly sensitive and selective detection of AFB(1) and ZEN in food samples with the limits of detection of 0.29 pg mL(-1) for AFB(1) and 0.22 pg mL(-1) for ZEN and the recoveries of 93.6%-103.2% for AFB(1) and 94.7%-105.1% for ZEN. This work also provides a novel universal PLNPs-based optical platform for the simultaneous detection of multiple contaminants in complex samples.