ZIF-L Derived Bimetallic N-Doped Porous Carbon-Prussian Blue Composite as Efficient Catechol Electrochemical Sensor

The development of effective and accurate catechol (CC) electrochemical sensors is critical for environment and life health perspectives. A facile pyrolysis of 2D bimetallic (Zn/Co) zeolitic imidazolate framework (Zn/Co-ZIF-L) was employed to prepare Zn and Co nanoparticles encapsulated in N-doped porous carbon (Zn/Co@NPC). Prussian blue (PB) was synthesized in-situ via the co-precipitation of ferricyanide ([Fe(CN)6]3-) and iron (Ⅱ) ion originated from the reduction of Fe3+ by Zn/Co@NPC and then served as the main active substance of CC detection. The morphology and composition of the final composite Zn/Co@NPC-PB were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and X-ray powder diffraction (XRD). The Zn/Co@NPC-PB modified glass carbon electrode (GCE) exhibits two concentration linear ranges of 4.13 μM -1.08 mM (R2 = 0.999) and 1.08 mM - 11.82 mM (R2 = 0.999) for CC electrochemical detection with a limit of detection 1.05 μM (S/N=3). At the same time, the biosensor shows great selectivity to electrochemical oxidation behavior of CC in presence of 20 folds dihydroxybenzene interferents such as hydroquinone and resorcinol. Furthermore, the Zn/Co@NPC-PB composite electrode showed a long-term stability and near 100% recovery for the detection of a real sample in Yellow River water.