A novel enzyme-free glucose and HO sensor based on 3D graphene aerogels decorated with NiN nanoparticles.

In this work, a novel enzyme-free glucose and hydrogen peroxide (HO) sensor based on NiN nanoparticles on conductive 3D graphene aerogels (NiN/GA) has been successfully synthesized by using hydrothermal reaction, freeze-dried and then calcined under NH atmosphere. The obtained NiN/GA composites were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), nitrogen adsorption-desorption isotherms and electrochemical methods. The results show the obtained 3D NiN/GA composites exhibit excellent electrochemical performance toward glucose oxidation and HO reduction with larger catalytic rate constant K value of 3.75 × 10 M s and 1.24 × 10 M s , respectively. As a glucose sensor, the obtained electrode provides a wide detection range of 0.1-7645.3 μM, fast response time within 3 s, high sensitivity of 905.6 μA mM cm and low detection limit of 0.04 μM. For detection of HO, this prepared sensor offers a wide detection range (5 μM-75.13 mM), fast response time (within 5 s), sensitivity (101.9 μA mM cm) and low detection limit (1.80 μM). This enzyme-free glucose and HO sensor display satisfactory selectivity, reproducibility and long-term storage stability. Additionally, the sensor can also be used for glucose and HO detection in human blood serum. The results demonstrate that 3D GA nanostructures provide an enviable conductive network for efficient charge transfer and avoid NiN nanoparticles aggregation, which is advantageous for electrocatalytic applications.