A new bifunctional electrochemical sensor for hydrogen peroxide and nitrite based on a bimetallic metalloporphyrinic framework. Issue 48 (19th November 2015) - Shi, Li-Mei
Abstract : The bimetallic electrocatalytic ability of a new metallic porphyrin, Cu-CoTCPP, toward redox of H2 O2 and oxidation of NaNO2 . Abstract : Metalloporphyrinic frameworks have been studied in many fields. However, their electrochemical properties were seldom reported. This work reports the synthesis and the electrochemical application of a new bimetallic metalloporphyrinic framework, [Cu2 -Co[5, 10, 15, 20-(4-carboxyphenyl)porphyrin](H2 O)2 ]·0.5DMF·5H2 O (Cu-CoTCPP) in which [5, 10, 15, 20-(4-carboxyphenyl)porphyrin]Co(ii ) (CoTCPP) struts are bound by Cu(ii )–carboxylate clusters (Cu2 (COO)4 ). Cu-CoTCPP was synthesized by the solvothermal method and characterized by various techniques, including XRD, IR, UV-vis, elemental analysis, TG, and TEM. Cu-CoTCPP showed novel bifunctional electrocatalytic ability toward the reduction/oxidation of H2 O2 and the oxidation of NaNO2, which might be due to Cu and Co central ions, respectively. With the assistance of multi-walled carbon nanotubes (MWCNTs), Cu-CoTCPP showed further improved sensing performance toward H2 O2 . The linear detection ranges of the Cu-CoTCPP/MWCNTs/GCE for H2 O2 and NaNO2 are 5.0 × 10 −7 to 1.8 × 10 −4 M and 2.5 × 10 −6 to 1.1 × 10 −3 M, respectively, with the detection limits of 2.4 × 10 −7 M and 1.7 × 10 −7 M, and the sensitivity of 168 and 439 mA mol −1 L cm −2 . The bifunctional electrocatalytic ability and the excellent performance imply that the metalloporphyrinic frameworks are promising candidates for fabricating electrochemical sensors.