A method for determination of glucose by an amperometric bienzyme biosensor based on silver nanocubes modified Au electrode

• Bienzyme sensor has highly sensitive, fast amperometric response to glucose with low detection limit.
• Silver nanocubes exhibited extremely high electrocatalytic activity due to their rich (1 0 0) faces.
• The catalytic cascade of Gox and HRP in the bienzyme sensor produced signal amplification.

This paper reported the fabrication of an amperometric glucose biosensor based on silver nanocubes (AgNCs) and horseradish peroxidase (HRP)–chitosan (CS)–glucose oxidase (Gox) bienzymatic film. The fabrication process was characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), and atomic force microscopy (AFM). Cyclic voltammetry (CV) and amperometry measurements were used to study and optimize the performance of the resulting peroxide biosensor. Under the optimal conditions, the sensor exhibits good electrocatalytic activity toward the oxidation of glucose, and this enables the determination of glucose in the 10 μM to 1.5 mM concentration range, with a detection limit at 0.6977 μM (at an S/N of 3). The response time is less than 5 s. The bienzymatic electrode presented a number of attractive features such as high sensitivity, low detection limit, fast response, and good stability, making this Gox–CS–HRP/AgNCs–CS nanocomposite film a promising candidate for glucose sensors.