Composite Material Based on Macroporous Polyaniline and Osmium Redox Complex for Biosensor Development

Here the feasibility of layers based on the conducting polymer polyaniline (PANI) as component of glucose biosensors using glucose oxidase (GOx) as enzyme and [Os(bpy)(2)(4-aminomethylpyridine)Cl]PF6 (OsCmplx) as electrochemical mediator, is evaluated. Particularly, PANI was employed to obtain a nanostructured macroporous material (m-PANI) around polystyrene nanoparticles taken as template and the mediator was co-immobilized during the polymerizing procedure. The GOx biosensor based on OsCmplx modified m-PANI provides a linear response to glucose concentration in the range 5 up to 65 mM with a sensitivity of 3.54 mu A/mM/cm(2) (on a projected geometric area=0.07 cm(2)), an LOD of 0.8 mM and a good precision (%RSD <= 7, n=5); the biosensor is stable showing a decrease of 10% to the value of the sensitivity after 15 days of use and of about 50% after 40 days.