3D hierarchical bayberry-like Ni@carbon hollow nanosphere/rGO hybrid as a new interesting electrode material for simultaneous detection of small biomolecules.

Metal-organic framework derived hierarchical bayberry-like Ni@carbon hollow nanosphere/reduced graphene oxide (Ni@CHS/rGO) hybrid was synthesized by combining a simple solvothermal reaction with a further annealing treatment. 3D hierarchical bayberry-like Ni@CHS/rGO hybrid not only offered a continuous highly conductive Ni metal and graphene matrix to facilitate the charge transfer, but also allowed uptaking and releasing of electrolytes and enchanted adsorbing of targets due to a hollow structure and introduction of graphene. Consequently, such a charming architecture displays preeminent electrocatalytic activity towards the electro-oxidation on ternary mixtures of ascorbic acid (AA), uric acid (UA) and dopamine (DA). For simultaneous detection of three small molecules, the fabricated sensor exhibited good application prospects toward analytes of DA, UA and AA. Furthermore, three well-separated voltammetry peaks were obtained using Ni@CHS/rGO electrode in differential pulse voltammetry (DPV) measurements. The calibration curves for UA, DA and AA were obtained: 0.25-126µM, 0.25-126µM and 2-4000µM, respectively, the detection limits were 0.05µM, 0.05µM, 0.37µM, respectively. This sensor exhibited excellent sensitivity, good stability, outstanding anti-interference ability and acceptable reproducibility. Moreover, the intriguing sensor was triumphantly applied for the quantitative analysis of UA, DA and AA in human urine and vitamin C tablets samples with satisfactory recovery, which manifests its viability application for practical analysis.