Reagentless amperometric detection of l-lactate on an enzyme-modified conducting copolymer poly(5-hydroxy-1,4-naphthoquinone-co-5-hydroxy-3-thioacetic acid-1,4-naphthoquinone).
We have constructed a reagentless lactate sensor using lactate oxidase (LOD) covalently attached to an electropolymerized copolymer film, poly(5-hydroxy-1,4-naphthoquinone-co-5-hydroxy-3-thioacetic acid-1,4-naphthoquinone), poly(JUG-co-JUGA). Around 10(-12)Mcm(-2) of covalently bound enzymes are immobilized on these films. In aerated medium, the amperometric response versus lactate concentration shows a sensitivity of 350 +/- 50 microAM(-1)cm(-2) for an applied potential of +0.5V versus Ag|AgCl on a film-coated Pt electrode. In deaerated medium, the quinone group, conjugated with the polymer backbone, acts as an immobilized mediator. An amperometric response is observed on film-coated glassy carbon (GC) electrode at a potential as low as -0.1V versus Ag|AgCl, with a sensitivity of 110 +/- 40 microAM(-1)cm(-2).
Haccoun
J
J
Laboratoire Interfaces Traitements Organisation et Dynamique des Systèmes (ITODYS) de l'Université Paris 7-Denis Diderot, associé au CNRS, UMR 7086, 1 rue Guy de la Brosse, 75005 Paris, France.
Piro
B
B
Tran
L D
LD
Dang
L A
LA
Pham
M C
MC
D015374:Biosensing Techniques / Q000295:instrumentation*; D019344:Lactic Acid / Q000032:analysis*; D006899:Mixed Function Oxygenases; D011108:Polymers
D011108:Polymers; D019344:Lactic Acid; D006899:Mixed Function Oxygenases; C021497:lactate 2-monooxygenase