A label-free enrofloxacin electrochemical aptasensor constructed by a semiconducting CoNi-based metal-organic framework (MOF)

A semiconducting CoNi-based metal-organic framework (MOF), CoxNi3-x,(HITP)(2), was designed and synthesized using 2,3,6,7,10,11-hexaaminotriphenylene (HATP) as organic linker. Compared with Co-3(HITP)(2) and Ni-3(HITP)(2), CoxNi3-x(HITP)(2) possesses mixed metal valences of Co2+/Co3+/Ni2+/Ni3+ and more defects within the MOF skeleton, which also shows amino-rich functionality, biocompatibility, and the intrinsic features of semiconducting MOFs, such as two-dimensional graphene-like nanostructure, high stability in water solution, and good electrochemical activity. As a consequence, the CoxNi3-x(HITP)(2)-based electrochemical aptasensor demonstrates superior sensing performances for enrofloxacin, with an extremely low detection limit of 0.2 fg.mL(-1) and a linear range of 0.001-1 pg.mL(-1), as well as high selectivity, excellent reproducibility, good stability, and wide applicability. The developed sensing strategy provides new insights into the fabrication of MOFs-based sensors for food safety, environment protection, and medical diagnosis. (C) 2020 Elsevier Ltd. All rights reserved.

Automated summary

A semiconducting CoNi-based metal-organic framework CoxNi3-x(HITP)(2) was designed and synthesized, showing mixed metal valences and more defects, which enables high sensitivity detection of enrofloxacin. The sensor exhibits good stability, reproducibility, and has promising applications in food safety, environmental protection, and medical diagnosis.