Amperometric Glucose Biosensor Based on a Pt-Dispersed Hierarchically Porous Electrode

Abstract

A high-performance electrochemical biosensor for the detection of glucose was developed using a Pt-dispersed polyaniline (PANI) nanorod electrode with a hierarchical porous surface. PANI nanorods were synthesized directly on an Au-coated porous silicon electrode and high-density Pt nanoparticles were dispersed on the PANI nanorods by electrochemical deposition. The electrode surface's structure exhibited order on multiple length scales from similar to 30-nm Pt nanoparticle to similar to 200-nm diameter PANI nanorod to micrometer pore size's for the porous silicon. The sensitivity of the Pt-dispersed PANI nanorod electrode with a hierarchical porous surface was 35.64 mu A/mM, which corresponds to a 22.1-fold larger value than that of the planar Au/PANI nanorod electrode. The glucose biosensor with a Pt-dispersed highly porous electrode exhibited a short response time (<10 s) and a linear response in the range from 9 x 10(-6) to 5 x 10(-3) M. The sensor also showed long-term stability; the sensing response measured under the same conditions retained 80 % of the initial value after a 45-day storage. The high performances of the novel glucose sensor are mainly attributed to the hierarchical porous electrode structure, which provides an increased sensing area and effective mass transportation pathway.