A silicon-based bulk micromachined amperometric microelectrode biosensor with consecutive platinization and polymerization of pyrrole

A new silicon-based amperometric microelectrode biosensor with consecutive platinization and polymerization of pyrrole is designed and fabricated with bulk micromachining technology. The biosensor consists of a p-type silicon substrate, two respective Au microelectrodes fabricated in two respective in-device micropools formed by anisotropic silicon wet etching, and an SU-8 microreaction pool. To our knowledge, consecutive platinization and polymerization of pyrrole is the first such use for surface modification. The biosensor aims for low unit cost, small dimensions and compatibility with CMOS technology. Successful experimental results have been achieved for glucose detection. Compared to conventional amperometric biosensors and amperometric microelectrode biosensors made with surface micromachining technology, it has several advantages, such as smaller sensitive surface area (1 mm × 1 mm), lower detection limit (1 × 10−4 M), larger linear range (1 × 10−4-1 × 10−2 M), larger sensitivity per unit area (39.640 nA mM−1 mm−2), better reproducibility (3.2% RSD for five detections) and stability (relative remaining sensitivity per unit area kept 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.