Fast cathodic reduction electrodeposition of a binder-free cobalt- doped Ni-MOF film for directly sensing of levofloxacin

To circumvent the binder's adverse effect on the performance of electrochemical sensor and improve the analysis efficiency, a binder-free cobalt-doped Ni-MOF (Co/Ni-MOF) film, with honeycomb-like structure, is fast electrodeposited on glassy carbon electrode (GCE) by cathodic reduction. No conductive agent added, the Co/Ni-MOF/GCE can be directly used as a sensor for levofloxacin (LEV) determination. Under the optimal condition, a wider linear range of 0.1 uM-500 mu M LEV is obtained with the limit of detection (LOD, 3S/N) being 22 nM and the sensitivity of 2.85 mu A W-1 cm(-2). Further, when being used to analysis of LEV in e ye drop and spiked milk, satisfactory recoveries of 94.0%-108.2% are achieved. Particularly, benefiting of the synergistic effect of Co2+ and Ni2+, as well as and the binder-free film, the sensor exhibits an excellent sensitivity and a robust long-term stability. This work develops a facile and efficient strategy to synthesis of Co and Ni based MOF film, and provides them a new way in electrochemistry application. (C) 2020 Elsevier B.V. All rights reserved.

Automated summary

A binder-free Co/Ni-MOF film was electrodeposited on a glassy carbon electrode to improve the performance of an electrochemical sensor. The sensor showed a wider linear range, lower detection limit, and higher sensitivity for levofloxacin detection, with satisfactory recoveries in eye drops and spiked milk. This work developed an efficient strategy for the synthesis of Co and Ni-based MOF films and demonstrated their potential in electrochemical applications.