Precisely quantified catalyst based on in situ growth of Cu2O nanoparticles on a graphene 3D network for highly sensitive glucose sensor

- Simple in situ growth of Cu2O nanoparticles on a G3DN.
- The quantity of Cu2O grown on the G3DN is precisely controlled.
- The in situ growth lead to a robust interface between Cu2O and G3DN.
- Preeminent analytical performance for glucose detection.
- The method to prepare electrode can be expanded to other electrochemical sensors.

Due to the fact that catalytic oxidation of glucose only takes place on the surface of catalysts, increasing the specific surface of catalysts is an effective way to achieve high catalytic performance. Herein, we have developed an effective and extremely simple method to prepare a highly sensitive and enzyme-free glucose sensor with precisely quantified catalyst, which is prepared by in situ growth of Cu2O nanoparticles on a hierarchical graphene 3D network grown on carbon paper (G3DN/CP). The sensitivity, detection limit, response time and linear range of the sensor are (2.31 ± 0.03) × 103 μA mM−1 cm−2, 0.14 ± 0.01 μM, 1.6 s and 0.48-1813 μM, respectively. In addition, the sensor can retain 95.5% of its initial sensitivity even after 10 days. Specifically, due to the precise quantification of Cu2O nanoparticles deposited on G3DN, it is beneficial to mass production and precisely controlling the performance of the glucose sensor devices for public healthcare and industry. This approach could be used for other electrochemical sensors.

The Cu2O/G3DN/CP electrode with precise quantification of Cu2O loading is fabricated by in situ growth and exhibits excellent analytical performance for glucose detection due to the high electrical conduction, large specific surface and fast electron transmission channels of G3DN, high catalytic capability of Cu2O nanoparticles, and the robust interface between Cu2O and G3DN.162