LAUSR

Abstract The bimetal-organic framework Cu-Ni-BTC (1,3,5-Benzenetricarboxylic acid, H3BTC) and its derivative CuO@NiO were used as the basis of the construction of electrochemical sensors for three environmental small-molecules. Firstly, the Cu-Ni-BTC-CPE modified electrode was investigated by electrochemical measurement, the results showed that linear responses of the proposed sensor ranged from 0.5 μM to 330 μM for catechol (CT) and 0.3 μM to 390 μM for hydroquinone (HQ), with detection limits of 0.2 μM and 0.08 μM, respectively. Secondly, CuO@NiO was prepared by calcination, and myoglobin (Mb) was subsequently immobilized on a sensing interface based on CuO@NiO and ionic liquid (IL) composite membrane where IL possessed good electrical conductivity, wide electrochemical potential window, excellent film forming as well as good biocompatibility. Spectroscopic and electrochemical examinations revealed that Mb remained its bioactivity on the surface of CuO@NiO/IL composite film, and had excellent electrocatalytic activity towards nitrite (NO2−) in ranges of 1.0–1536 μM and 1536–3636 μM, and the detection limit was low to 0.4 μM, the apparent Michaelis-Menten constant (KM) was 0.42 mM. The results showed that MOFs and its derivative have different catalytic performance. The biggish difference in catalyst activity and selectivity provides a new idea and theoretical guidance for the further studies on electrochemical sensors.