Monoenzymatic Lipase Potentiometric Biosensor for the Food AnalysisBased on a pH Sensitive Graphite-epoxy Composite as Transducer

In this paper the development of a potentiometric biosensorbased on the use of the enzyme lipase immobilized in a Nafionmembrane on a graphite-epoxy transducer is reported. This device hasbeen used to quantify triglycerides in food samples from the aqueousextracts obtained by emulsion with Arabic gum. The proposedmethodology does not present significant differences with the spectrophotometricdetermination used as contrast. This work constitutesthe first report of a potentiometric biosensor based on the detection ofchanges of pH using a graphite-epoxy composite transducer and thefirst potentiometric triglyceride biosensor which is not based in ISFETtransducers. The methodology designed is a simple and inexpensivealternative that minimizes the use of organic solvents without affectingthe precision and accuracy of the analysis in complex food samplessuch as butter, chips and pastries.