Manganese porphyrin wrapped DNA dendrimer as a universal chemiluminescence tag for ultrasensitive and multiplex assay of mycotoxins.

A manganese porphyrin wrapped DNA dendrimer (Mn-DD) was developed through enzyme-free DNA self-assembly and simple and mild groove binding of porphyrin. The Mn-DD not only possessed plenty of manganese porphyrin to amplify the chemiluminescence (CL) signal, but also can be modified with diverse groups via DNA hybridization. Combined with an immunosensor array, Mn-DD can be utilized for CL immunoassay of multiple mycotoxins as a universal tag. Under optimal conditions, Mn-DD-based CL imaging immunoassay of aflatoxin B (AFB), ochratoxin A (OTA), and zearalenone (ZEN) exhibited broad linear ranges over 4 orders of magnitude and detection limits as low as 0.87, 0.75, and 0.79 pg mL, respectively. It was also utilized in the examination of real coix seed samples, yielding reliable results. High sensitivity, as well as simple operation, low reagent dosage, acceptable accuracy and stability showed the tag and the approach broad application prospects in quality control of food and medicine.