Study of the one-step in situ growth synthesis of Cu-Pic coordination polymer and Cu-BTC MOF and their performances for detection of 4-Nitrophenol

Herein we report the one-step in situ growth of Cu-Pic coordination polymer (Cu-Pic CP) and Cu-BTC metal-organic framework (MOF) for the first time. The oxidation of copper substrate to Cu2+ ions and their reaction with the organic ligands is performed simultaneously. Then the grown crystals can be easily removed from the surface by shaking. Both compounds are characterized using single crystal (SXRD) and (PXRD) X-ray diffraction analysis, infrared analysis (FTIR), energy dispersive X-ray analysis (EDX), field emission electron microscopy (ESEM), Brunauer-Emmett-Teller (BET) surface area analysis, and the thermal gravimetric analysis (TGA). CuBTC MOF and Cu-Pic CP were used to modify carbon paste (CPE/Cu-Pic and CPE/Cu-BTC) to study their electrocatalytic performances for sensing 4-nitrophenol (4-NP). For CPE/Cu-Pic, the responses were linear in the concentration range of 1.2-70 mu M with a detection limit of 90 nM (S/N = 3), while for CPE/Cu-BTC the responses were linear in the ranges of 0.7-10 and 10-100 mu M with a detection limit of 40 nM (S/N = 3). Furthermore, the excellent selectivity, repeatability of signals, and recovery values in the range of 96-102% and 98.0-104.0% for CPE/Cu-Pic and CPE/Cu-BTC, respectively, verified the suitability of the two sensors for monitoring 4-NP levels in environmental water samples.