Covalent organic framework derived Fe3O4 / N co-doped hollow carbon nanospheres modified electrode for simultaneous determination of biomolecules in human serum

In this work, Fe3O4/N co-doped hollow carbon spheres (Fe3O4@NHCS) as a promising electrocatalysis material had been prepared through carbonizing covalent organic frameworks and ferric irons. The morphology, structure, composition and electrocatalytic performance of Fe3O4@NHCS were characterized by various techniques. The electrode modified with Fe3O4@NHCS (Fe3O4@NHCS/GCE) exhibited excellent electrocatalytic activity for the oxidation of dopamine, uric acid, guanine and adenine. Simultaneous determination of these biomolecules was successfully achieved with Fe3O4@NHCS/GCE. Under the optimum conditions, the linear ranges for the determination of dopamine, uric acid, guanine and adenine were 0.01-40, 0.10-40, 0.50-30 and 0.50-40 μmol/L with the correlation coefficients of 0.9905, 0.9906, 0.9919 and 0.9908, respectively. The detection limits were 6.3, 36.1, 143.2 and 123.5 nmol/L for dopamine, uric acid, guanine and adenine, respectively (S/N = 3). In addition, the modified electrode was also applied to the simultaneous determination of these biomolecules in human serum samples and the recovery were varied from 97.6% to 104.2%. The results demonstrated that the Fe3O4@NHCS modified electrode had the characteristics of high sensitivity, good selectivity and reliability.