A disposable, reagentless, third-generation glucose biosensor based on overoxidized poly(pyrrole)/tetrathiafulvalene-tetracyanoquinodimethane composite.
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.
Palmisano
Francesco
F
Dipartimento di Chimica, Università di Bari, Via Orabona, 4-70126 Bari, Italy. palmisano@chimica.uniba.it
Zambonin
Pier Giorgio
PG
Centonze
Diego
D
Quinto
Maurizio
M
D015374:Biosensing Techniques / Q000379:methods* / Q000592:standards; D004563:Electrochemistry; D004566:Electrodes; D004800:Enzymes, Immobilized; D005947:Glucose / Q000032:analysis*; D005949:Glucose Oxidase; D006571:Heterocyclic Compounds / Q000737:chemistry; D009570:Nitriles / Q000737:chemistry; D010084:Oxidation-Reduction; D011108:Polymers / Q000737:chemistry; D011758:Pyrroles / Q000737:chemistry; D012680:Sensitivity and Specificity
D004800:Enzymes, Immobilized; D006571:Heterocyclic Compounds; D009570:Nitriles; D011108:Polymers; D011758:Pyrroles; C013703:tetracyanoquinodimethane; C067635:polypyrrole; D005949:Glucose Oxidase; C063887:tetrathiafulvalene; D005947:Glucose