Multimicrobial Sensor Using Microstructured Three-Dimensional Electrodes Based on Silicon Technology

• Published in: Analytical chemistry (Washington) Vol. 72; no. 9; pp. 2022 - 2028
• Main Authors: König, Andreas, Reul, Thomas, Harmeling, Christian, Spener, Friedrich, Knoll, Meinhard, Zaborosch, Christiane
• Format: Journal Article
• Language: English
• Published: Washington, DC American Chemical Society 01.05.2000
• Subjects: Biodegradation, Environmental; Biological and medical sciences; Biosensing Techniques; Biosensors; Biotechnology; Candida - chemistry; Electronics; Environment and pollution; Fundamental and applied biological sciences. Psychology; Industrial applications and implications. Economical aspects; Measuring instruments; Methods. Procedures. Technologies; Microcomputers; Microelectrodes; Miscellaneous; Semiconductors; Silicon; Sphingomonas - chemistry; Various methods and equipments; Hydrocarbon; Sphingomonas; Polycyclic aromatic compound; Chip; Candida parapsilosis; Waste water; Fungi; Pollutant; Microbial electrode; Biosensor; Biological oxygen demand; Bacteria; Silicon; Fungi Imperfecti; Entrapped microorganism; Thallophyta
• ISSN: 0003-2700; 1520-6882
• DOI: 10.1021/ac9908391

Two microbial strains with different substrate spectra were immobilized separately within a single biosensor chip featuring four individually addressable platinum electrodes. These were sputtered onto the inner surface of four isolated pyramidal cavities (“containments”) micromachined on a silicon wafer. The biosensor chip was integrated into a flow-through system to measure the oxygen consumption of the immobilized microorganisms in the presence of assimilable analytes. As a model system, a yeast for the determination of biochemical oxygen demand (BOD) and a strain capable of degrading polycyclic aromatic hydrocarbons (PAH) were chosen. It was shown that the simple and mass-producible containment sensor exhibits good performance data:  lower detection limit 0.1 mg/L naphthalene and 1 mg/L sensor-BOD; calibration range up to 30 mg/L; precision 3−6%; response time 2−3 min; service life up to 40 days; shelf life at 4 °C 6 months. The versatility of the multimicrobial sensor was demonstrated by measuring ordinary municipal wastewater samples as well as various aqueous samples contaminated with PAH. The concept of a multimicrobial sensor not only enlarges the substrate spectrum for sum parameters such as BOD but leads to additional information which allows for a more differentiated and immediate knowledge of sample composition. Using chemometrical data analysis, the multimicrobial sensor lays a foundation for developing an “electronic tongue”.