In situ fabrication of Cu-bipy-BTC Metal-organic Framework Electrode for Catechol Detection

In this work, the metal organic frameworks (MOFs) Cu-bipy-BTC ([Cu-2(OH)(2,2'-bipy)(2)(BTC)(3)2H(2)O](n)) were in situ synthesized on the surface of a gold electrode directly to form a hybrid material of a Cu(OH)(2) nanosheet and Cu-bipy-BTC nanoparticle. The structure of this hybrid material on the electrode surface was characterized using Fourier-transform infrared spectroscopy, X-ray diffraction, scanning electron microscopy, and energy-dispersive spectrocopy. It is shown that the newly in situ synthesized Cu-bipy-BTC MOF can serve as active metal centers, and is embedded in different hydrophobic environments formed by Cu(OH)(2) nanosheets. This unique structure is very similar to that of an active site of laccase, giving better catalytic activity. This MOF-based electrode enables the catalytic oxidation of catechol at +0.4 V (versus Ag/AgCl). The amperometric responses are linear with concentrations of catechol ranging from 10 to 250 mu M and 250 to 1000 mu M with sensitivities of 1.6224 and 0.2591 mu A . cm(-2). mu M-1, respectively. Compared with other catechol electrochemical sensors, this MOF-based electrode has advantages of higher sensitivity and easy manufacturability, facilitating its potential application in the detection of catechol.