Related Experiment Videos
A disposable, reagentless, third-generation glucose biosensor based on overoxidized
Francesco Palmisano1, Pier Giorgio Zambonin, Diego Centonze
1Dipartimento di Chimica, Università di Bari, Via Orabona, 4-70126 Bari, Italy. palmisano@chimica.uniba.it
Abstract:
A disposable glucose biosensor based on glucose oxidase immobilized on tetrathiafulvalene-tetracyanoquinodimethane (ITF-TCNQ) conducting organic salt synthesized in situ onto an overoxidized poly(pyrrole) (PPy(ox).) film is described. The TIF-TCNQ crystals grow through the nonconducting polypyrrole film (ensuring electrical connection to the underlying Pt electrode) and emerge from the film forming a treelike structure. The PPy(ox) film prevents the interfering substances from reaching the electrode surface. The sensor behavior can be modeled by assuming a direct reoxidation of the enzyme at the surface of the TTF-TCNQ crystals. A heterogeneous rate constant around 10(-6) - 10(-7) cm s(-1) has been estimated. The biosensor is nearly oxygen- and interference-free and when integrated in a flow injection system displays a remarkable sensitivity (70 nA/mM) and stability.