Core-shell composite N-doped-Co-MOF@polydopamine decorated with Ag nanoparticles for nonenzymatic glucose sensors

A novel core-shell composite N-doped-Co-MOF@polydopamine (N-Co-MOF@PDA) decorated with Ag nanoparticles was initially synthesized, and further utilized to design electrochemical sensors of nonenzymatic glucose. More importantly, it was found that dopamine (DA) could effectively and rapidly self-polymerize on the surface of N-Co-MOF, because N-Co-MOF might have the ability to catalyze DA self-polymerization. Afterwards, as-prepared N-Co-MOF@PDA was performed as reducing agent, which could in situ transform Ag+ ions to Ag nanoparticles with uniform size, high dispersion and good conductivity. Finally, a non-enzymatic sensor was developed based on composite N-Co-MOF@PDA-Ag with good performance for the electrocatalytic oxidation of glucose due to the synergetic effect between N-Co-MOF and Ag nanoparticles. N-CoMOF@PDA-Ag-based glucose sensor exhibits the wide linear range from 1 mu M to 2 mM, with a limit of detection down to 0.5 mu M (S/N = 3), as well as good selectivity, long-time stability and great reproducibility. Furthermore, the feasibility of practical applicability for glucose detection was witnessed in the actual samples of human serum with satisfactory consequence. These results suggest that N-Co-MOF@PDA-Ag composite may be a promising candidate for the construction of non-enzymatic sensor.

Automated summary

A novel core-shell composite N-doped-Co-MOF@polydopamine (N-Co-MOF@PDA) decorated with Ag nanoparticles was synthesized and utilized to design a non-enzymatic glucose sensor. The composite material demonstrated excellent electrocatalytic oxidation performance for glucose due to the synergistic effect between N-Co-MOF and Ag nanoparticles. The sensor exhibited a wide linear range, low detection limit, good selectivity, long-term stability, and reproducibility. The practical applicability for glucose detection in human serum was also demonstrated. These findings suggest that the N-Co-MOF@PDA-Ag composite is a promising candidate for non-enzymatic sensor construction.