Amperometric glucose biosensor based on a Pt-dispersed hierarchically porous electrode

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 ∼30-nm Pt nanoparticle 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 μA/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 × 10 ^-6 to 5 × 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.