Fabrication of an Amperometric Glucose Biosensor Based on a Prussian Blue/Carbon nanotube/Ionic Liquid Modified Glassy Carbon Electrode

An amperometric glucose biosensor was developed based on synergistic contributions of PB and a bucky gel (BG) consisting of carbon nanotubes (CNTs) and ionic liquid (IL). The PB nanoparticles were first deposited onto the surface of a BG modified glassy carbon (GC) electrode (BG/GC). Then, the Ni2 ions were electrochemically inserted into the PB lattice to improve its stability in physiological pH. Afterwards, Glucose oxidase (GOx) was immobilized on the BG/GC electrode using a cross-linking method. Amperometric measurements of glucose were performed at −0.05 V vs. Ag/AgCl in 0.05 M phosphate buffer solution at pH 7.4. The glucose biosensor exhibited a sensitivity of 45.03 µA mM−1 cm−2 with a detection limit of 5×10-7 M. The amperometric response was linear in the range of 5×10-7 to 8.3×10−4 M.