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

<p>One-pot solvothermal treatment of Co(NO<sub>3</sub>)<sub>2</sub>·6H<sub>2</sub>O, H<sub>2</sub><b>L</b> (5-(3-methyl-5-(pyridin-4-yl)-4<i>H</i>-1,2,4-triazol-4-yl) isophthalic acid), and 4,4<i>′</i>-bipyridine (4,4<i>′</i>-bipy) in H<sub>2</sub>O/DMF (V/V = 1 : 1) yielded a cobalt-organic chain, [Co(<b>L</b>)(O)(H<sub>2</sub>O)<sub>2</sub>]<sub>n</sub>·1.25nH<sub>2</sub>O (<b>1</b>). Compound <b>1</b> as raw materials was calcined to obtain Co<sub>3</sub>O<sub>4</sub>, which could be confirmed by PXRD and SEM. Via the modification, Co<sub>3</sub>O<sub>4</sub>@SiO<sub>2</sub>-NH<sub>2</sub> and Co<sub>3</sub>O<sub>4</sub>@SiO<sub>2</sub>-NH<sub>2</sub>-FA samples could be obtained. Compared to Co<sub>3</sub>O<sub>4</sub>@SiO<sub>2</sub>-NH<sub>2</sub>, Co<sub>3</sub>O<sub>4</sub>@SiO<sub>2</sub>-NH<sub>2</sub>-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.</p>