Electrosynthesized non-conducting polymers as permselective membranes in amperometric enzyme electrodes: a glucose biosensor based on a co-crosslinked glucose oxidase/overoxidized polypyrrole bilayer.
A glucose amperometric biosensor based on glucose oxidase immobilized on an overoxidized polypyrrole (PPyox) platinum modified electrode, by glutaraldehyde co-crosslinking with bovine serum albumine, is described. The advantages of covalent immobilization techniques (e.g. high loading and long-term stability of the enzyme) are coupled with the excellent interferent rejection of electrosynthesized non-conducting polymers. The sensor showed an apparent Michaelis-Menten constant of 16 +/- 0.8 mM, a maximum current density of 490 microA/cm2 and a shelf lifetime of at least 3 months. Ascorbate, urate, cysteine and acetaminophen at their maximum physiological concentrations produced a glucose bias in the low micromolar range. Flow-injection response was linear up to 20 mM glucose with typical sensitivity of 84.0 +/- 1.5 nA/mM. The sensor was tested for glucose determination of untreated serum samples from both normal and diabetic subjects; results of amperometric assay compared well with those obtained by a standard enzymatic-colorimetric method.
Guerrieri
A
A
Dipartimento di Chimica, Università della Basilicata, Potenza, Italy. guerrieri@unibas.it
De Benedetto
G E
GE
Palmisano
F
F
Zambonin
P G
PG
D000818:Animals; D015374:Biosensing Techniques; D002417:Cattle; D004800:Enzymes, Immobilized; D005947:Glucose / Q000032:analysis*; D005949:Glucose Oxidase; D006801:Humans; D011108:Polymers; D011758:Pyrroles; D012680:Sensitivity and Specificity
D004800:Enzymes, Immobilized; D011108:Polymers; D011758:Pyrroles; C067635:polypyrrole; D005949:Glucose Oxidase; D005947:Glucose