Construction of an amperometric triglyceride biosensor using PVA membrane bound enzymes.

OBJECTIVES A method is described for construction of an amperometric triglyceride (TG) biosensor using PVA membrane bound enzymes. DESIGN AND METHODS A mixture of commercial lipase, glycerol kinase, glycerol-3-phosphate oxidase and horseradish peroxidase was co-immobilized onto polyvinyl alcohol (PVA) membrane through glutaraldehyde coupling. The biosensor measures current when polarized at 0.4 V. RESULTS The sensor showed optimum response within 2 s at pH 7.0 and 25 degrees C. The current (mA) was in proportion to concentration of TG in the range 0.56-2.25 mM. The minimum detection limit of the method was 0.21 mM. The analytic recovery of added TG was 94.3%. Within batch and between batch coefficients of variations (CV) were <5.85% and <4.13%, respectively. A good correlation (r=0.99) was found. Among various serum substances tested, only cholesterol caused slight stimulation (20%). CONCLUSIONS An amperometric method was developed for determination of TG employing this enzyme electrode.