AN AMPEROMETRIC FLOW-INJECTION ANALYSIS ENZYME SENSOR FOR SUCROSE USING A TETRACYANOQUINODIMETHANE MODIFIED GRAPHITE PASTE ELECTRODE

A flow injection analysis (FIA) enzyme sensor for sucrose is described . Two approaches were employed for the construction of the biosensor. In the first approach, the enzymes invertase and mutarotase were coval ently coupled to controlled pore glass (CPG) particles and placed in a packed bed reactor. Glucose oxidase (GOD) and the electron transfer m ediator tetracyanoquinodimethane (TCNQ) were incorporated into the gra phite paste electrode. In the second approach, invertase, GOD and TCNQ were incorporated into the graphite paste electrode. The first system was capable of measuring sucrose in a concentration range of 0.025-20 0 x 10(-3) mol/l, whereas the second system was able to measure sucros e concentrations up to 2000 x 10(-3) mol/l. Assay times were 6 min wit h the first system and 12 min with the second system. (C) 1996 Elsevie r Science Limited