Electrochemical sensing of trimethylamine based on polypyrrole-flavin-containing monooxygenase (FMO3) and ferrocene as redox probe for evaluation of fish freshness.

Amperometric and impedimetric biosensor for detecting trimethylamine (TMA) which represents good parameters for estimating fish freshness has been developed. The biosensor is based on a conducting polypyrrole substituted with ferrocenyl, where flavin-containing monooxygenase 3 (FMO3) enzyme was immobilised by covalent bonding. FMO3 catalyzes the monooxygenation TMA to trimethylamine N-oxide (TMO).