Electrochemical Sensors Based on Copper-Cadmium Bimetallic Porphyrin Coordination Polymers with Various Cu/Cd Ratios

Bimetallic porphyrin coordination polymers with various Cu/Cd ratios (Cu-Cd) were synthesized and characterized by X-ray diffraction, infrared spectroscopy, inductively coupled plasma atomic emission spectrometry and transmission electron microscopy. The presence of Cu(II) in the series of bimetallic porphyrin coordination polymers makes them electrochemically active, consequently, they can be used in electrochemical sensing of hydrogen peroxide and sodium nitrite. Their sensing performance was investigated by cyclic voltammetry and chronoamperometry. The performance was affected by Cu/Cd ratio of Cu-Cd, and the optimal Cu-Cd-2 (with Cu/Cd ratio of 1.59) showed the best performance: the detection sensitivities for H2O2 and NaNO2 were 414 and 418 mA/(M cm(2)), respectively, and detection limits were 2.7 and 3 mu M (S/N = 3). These results demonstrate that Cu-Cd offers great prospect for the construction of non-enzymatic sensors for hydrogen peroxide or sodium nitrite.