Towards a dual in-line electrochemical biosensor for the determination of glucose and hydrogen peroxide.

Herein, we report the development of a sensitive and selective dual mode electrochemical platform for the detection of glucose and H2O2. The platform is based on tungsten and gold microwire electrodes decorated with gold nanoparticles (AuNPs) and colloidal platinum (colloidal-Pt), respectively. The nanostructured AuNPs electrode was used as a support matrix for the immobilization of horseradish peroxidase (HRP) and the colloidal-Pt served as the non-enzymatic glucose biosensor in the construction of a dual in-line electrochemical biosensor that provides a microenvironment for HRP and a pathway for analyte diffusion via the high surface area. The dual-mode approach allows for the simultaneous detection of glucose and H2O2. The glucose biosensor exhibited a dynamic linear range of 0.5 mM to 8 mM glucose. Linearity for H2O2 was up to 70 μM. Operational stability resulted in 75% of the initial biosensor response after 27 days. The dual in-line biosensor showed good sensitivity of 0.403 mA mM-1 cm-2 for glucose and 0.193 mA mM-1 cm-2 for H2O2 in addition to good anti-interference ability. Thus, the low-cost and simple dual in-line biosensor can be used for the real-time detection of glucose and H2O2 in the clinical, biological and environmental fields.