Modification, characterization and peroxidase-mimetic properties of calcined product of a cobalt compound

One-pot solvothermal treatment of Co(NO3)2·6H2O, H2L (5-(3-methyl-5-(pyridin-4-yl)-4H-1,2,4-triazol-4-yl) isophthalic acid), and 4,4′-bipyridine (4,4′-bipy) in H2O/DMF (V/V = 1 : 1) yielded a cobalt-organic chain, [Co(L)(O)(H2O)2]n·1.25nH2O (1). Compound 1 as raw materials was calcined to obtain Co3O4, which could be confirmed by PXRD and SEM. Via the modification, Co3O4@SiO2-NH2 and Co3O4@SiO2-NH2-FA samples could be obtained. Compared to Co3O4@SiO2-NH2, Co3O4@SiO2-NH2-FA seems to have better peroxidase-mimetic properties. UV–vis results showed that optimal conditions of peroxidase-mimetic experiments were at 50°C in sodium acetate-acetic acid buffer (pH 3.6, 0.2 M), when the concentration of tetramethylbenzidine (TMB) was 0.2 mM. A concentration-dependent manner was shown between the concentration of glucose and absorbance in the measurement experiments for glucose.