Development of an amperometric enzyme electrode biosensor for fish freshness detection

A biosensor system has been developed for quantitative measurement of fish freshness by determining the ATP degradation products, hypoxanthine (HX), inosine (INO) and inosine monophosphate (IMP) metabolites in fish- tissue. Freshness is indicated by an index K-1 or H which depends on the amount of these ATP degradation products present in fish meat. These degradation metabolites have been detected efficiently by amperometric method using three new ferrocene carboxylic acid (FCA) mediator incorporated conducting polypyrrole enzyme electrodes with immobilized xanthine oxidase, nucleoside phosphorylase and nucleotidase enzymes for quantitative measurement of HX, INO and IMP respectively. This simple, fast and ready to use biosensor has been used to measure the H values of fresh water fish Catla-Catla over days of storage. Results show that the fish degrades very rapidly after 7 days even when stored at -12 degrees C. (C) 1998 Elsevier Science S.A. All rights reserved.