Conductive bimetallic metal–organic framework enforced electrochemical biosensor for high-performance monitoring Escherichia coli O157:H7 in animal derived food

In this work, a versatile conductive bimetallic metal–organic framework combined with aptamer enhanced electrochemical biosensor based on glassy carbon electrode (CMOF/Apt/GCE) was successfully developed for highly sensitive and selective detection of E. coli O157:H7 in animal derived food. The CMOF with large surface area provided an abundance of binding sites for aptamers, which greatly enhancing the selectivity of sensor for E. coli O157:H7. Furthermore, the excellent conductivity of CMOF dramatically improves the electron transfer rate on the modified surface of GCE, contributing to sensitively sensing of E. coli O157:H7. Based on CMOF/Apt/GCE, the E. coli O157:H7 was detected with a low limit of 2.5 CFU·mL −1 and a wide detection range from 10 to 10 7  CFU·mL −1 , superior than those of most previous works. Moreover, it can be applied to pork, chicken, and shrimp samples with good recovery, which indicated its great potential in practical food safety monitoring.