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

Abstract

A novel core–shell composite [email protected] ([email protected]) 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 [email protected] 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 [email protected] with good performance for the electrocatalytic oxidation of glucose due to the synergetic effect between N-Co-MOF and Ag nanoparticles. [email protected] glucose sensor exhibits the wide linear range from 1 μM to 2 mM, with a limit of detection down to 0.5 μM (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 [email protected] composite may be a promising candidate for the construction of non-enzymatic sensor.