Trimethylamine biosensor with flavin-containing monooxygenase type 3 (FMO3) for fish-freshness analysis

Trimethylamine (TMA) biosensor was constructed by immobilizing flavin-containing monooxygenase type-3 (FMO3), as one of drug metabolizing enzymes in human liver, onto a sensitive area of a dissolved oxygen electrode. The FMO3 immobilized sensor with flow injection analysis (FIA) was calibrated against trimethylamine solutions (putrefactive substance of fish) from 1.0 to 50.0 mmol/l, with good reproducibility in the repeatedly measurements (coefficient of variation: 4.39%, n = 5). By applying the TMA sensor for a fish-freshness analysis with extractions of horse-mackerel, the sensor output increased with the holding time of fish samples at 25 degreesC because of their decomposition. The TMA sensor with FMO3 would be convenient device for evaluating fish freshness. (C) 2004 Elsevier B.V. All rights reserved.