Fabrication of silicon-based bulk micro-machined amperometric microelectrode biosensor

A new silicon-based bulk micro-machined amperometric microelectrode biosensor, especially its fabrication, is provided. We designed the biosensor and fabricated it with anisotropic silicon wet etching. P-type silicon wafers are used as substrates, and Au and SU-8 are used for making electrodes and micro reaction pools, respectively. To our knowledge, consecutive platinization and polymerization of pyrrole is firstly used for surface modification. Successful experimental results have been achieved for glucose detection. It has several advantages, such as smaller sensitive surface area (1 mm/spl times/1 mm), lower detection limit (1/spl times/10/sup 4/ M), broader linear range (1/spl times/10/sup -4/ -1/spl times/10/sup -2/ M), larger sensitive coefficient (39.640 nA/spl middot/mm/sup -2//sub /spl middot//mM/sup -1/), better replicability (RSD 3.2% for five respective detections) and stability (sensitive coefficient remains well above 95% after being stored in a clean container at room temperature for a month), easier to be made into arrays and to be integrated with processing circuitry, etc.