Metal–oxygen clusters as peroxidase mimics for their multifarious applications in colorimetric sensors

Metal-oxygen cluster (Fe28) was certified to own inherent peroxidase-like performance, which could catalyze the oxidation of the peroxidase substrate 3,3’,5,5’-tetramethylbenzidine (TMB) using H2O2 in the aqueous solution for the first time. The compound Fe28 as peroxidise mimetics displayed multi-functional applications in H2O2, glucose and dopamine detection. The TMB/Fe28/H2O2 system supplied a simple colorimetric approach to detect H2O2 and glucose with good sensitivity and had a linear range from 2.62×10-5 mol/L to 1.57×10-4 mol/L and 3.92×10-6 mol/L to 3.14×10-5 mol/L, respectively. Moreover, the Fe28 cluster could detect dopamine without H2O2 with a linear range from 4.62×10-5 mol/L to 4.16×10-4 mol/L. Moreover, the Fe28 cluster was low-priced, easily to synthesize and extremely effective in the colorimetric assay, which can lead to new opportunities for the developments and applications of metal-oxygen clusters.