Bienzymatic glucose biosensor based on three dimensional macroporous ionic liquid doped sol–gel organic–inorganic composite

A novel three dimensional macroporous (3DM) ionic liquid (IL) doped poly (N[3-(trimethoxysilyl)propyl]aniline) (PTMSPA) inverse opal film was presented. The fabrication involved a self-assembly directed one-pot electrochemical process, which avoided the tediousness in the multi-step procedures. PTMSPA has the silicate network as well as the covalently linked polyaniline (PANI) chains within silica framework. The 3DM-PTMSPA-IL modified electrode showed superior performances over the individual components. Bienzymes, horseradish peroxidase (HRP) and glucose oxidase (GOD) were immobilized on the electroactive film with Nafion (Nf), thus, the modified electrode was designated as Nf-GOD-HRP/3DM-PTMSPA-IL/ITO. Electrochemical behavior of the biosensor was investigated by electrochemical impedance spectroscopy (EIS), cyclic voltammetry (CV) and chronoamperometry. Under the optimized conditions, the bioelectrocatalytic response currents revealed good linear relationship in the glucose concentration ranges of 0.05–1.0 mM and 1.0–8.0 mM with a detection limit of 0.01 mM. Furthermore, the detection of glucose levels in human sera showed satisfactory agreement with the clinical method.