The phosphomolybdate hybrids based on nanoscale heteropoly blue and metal-organic chain for supercapacitor and dual-functional electrochemical biosensor

The metal-organic complexes/chains were implanted into the basket-shaped heteropoly blue to yield two organic-inorganic hybrids, (H2bpy)5[{Co(H2O)2}{Co(H2O)3(bpy)}2{SrP6MoV2MoVI16O73}2]·8H2O (1) and (H2imi)(H2pz)(pz)2[{Zn(H2O)2(pz)}{Zn(H2O)3(pz)}{SrP6MoV2MoVI16O73}]·4H2O (2), (bpy = 4,4′-bipyridine; imi = imidazole; pz = pyrazines). Compound 1 is a 3D supramolecular hybrid net based on single-supported basket-shaped dimer. The basic unit of 2 is a unique dimeric chain built by metal-organic chains {Zn(H2O)2(pz)}n alternately anchoring two kinds of spatially oriented bi-arm basket dimers, which are extended into a staggered 3D hybrid network with 1-D regular tunnels inside the molecule. Compound 2 possess more prominent redox ability than 1 and most reported POM-based materials due to its structural advantages. 2-CPE presents excellent pseudocapacitive properties with high specific capacity and rate capability. A supercapacitor equipment (2-CPE//AC-CPE) shows superhigh energy density (40.2 Wh kg−1), power density (580.3 W kg−1), capacitance retention (91.89 %) and coulomb efficiency (98.05 %) after 10,000 cycles of GCD. In addition, 2-AB-GCE can be used as a dual-function sensor for hydrogen peroxide (H2O2) and dopamine (DA), which is outstanding in including linear range, detection line and feasibility evaluation. The recoveries of the two substrates were tested using human urine samples as background to evaluate their utility.