A sensitive bimetallic copper/bismuth metal-organic frameworks-based aptasensors for zearalenone detection in foodstuffs

Electrochemical aptasensors have emerged as promising platforms for effectivelydetection of various target analytes. Here, we developed a sensitive and selective electrochemical aptasensor for zearalenone (ZEN) determination based on a bimetallic organic framework (CuBi-BPDC). The results of HR-TEM, FE-SEM, XPS, etc. indicate the CuBi-BPDC possessing mixed nodes of Cu(II) and Bi(III) and multilayered nanosheets bearing nanoparticles. Due to its improved electrochemical activity and strong affinity for aptamers, the CuBi-BPDCbased aptasensor obtains a low limit of detection of 0.19 fg mL-1 (IUPAC S/N = 3) in a wide range of 1 fg mL- 1-10 ng mL-1 via EIS and 0.73 fg mL-1 from 0 fg mL-1 to 1 x 107 fg mL-1 via DPV for ZEN detection, respectively. Moreover, the excellent selectivity allows this aptasensor to specifically identify ZEN from other interfering substances in raw milk and rice, indicating the potential applicability of the CuBi-BPDC-based aptasensor in sensitive and selective detection of ZEN.