A sensitive electrochemiluminescence resonance energy transfer system between Ru-MOFs and Bi2S3 for deoxynivalenol detection

This study reports the fabrication of a novel "off-on" electrochemiluminescent (ECL) aptsensor based on ECL resonance energy transfer (RET) for the detection of deoxynivalenol (DON) in wheat and corn. Ru-MOF nanosheets (Ru-MOFs) using tris (4,4′-dicarboxylic acid-2,2′-bipyridine) ruthenium(II) as organic ligands exhibited a high ECL intensity. However, in the presence of Bi2S3 nanorods, the ECL intensity of Ru-MOFs was significantly quenched owing to the efficient ECL-RET system. The function of the Ru-MOFs and Bi2S3 nanorods as ECL energy donors and acceptors, respectively, were thoroughly investigated. For the construction of ECL-RET based aptasensor, a complementary sequence (cDNA) was immobilized onto Bi2S3 @AuNPs to improve the binding efficiency on the sulfhydryl-modified aptamer (SH-Apt), thus reducing the distance between the donors and acceptors and triggering ECL-RET. In the presence of DON, the specificity and strong binding of DON to Apt induced a drop in Bi2S3 @AuNPs-cDNA on the Ru-MOFs surface, thus restoring the ECL intensity. Under optimized conditions, the ECL biosensor showed excellent linearity over the concentration range of 0.01–500 μg kg−1 DON and a low detection limit of 9 × 10−3 μg kg−1 (S/N = 3). Consequently, the proposed strategy provides an effective analytical tool for food safety detection and drug analysis.