An in situ electrosynthesized amperometric biosensor based on lactate oxidase immobilized in a poly-o-phenylenediamine film: determination of lactate in serum by flow injection analysis.
The electrochemical immobilization of lactate oxidase in a poly-o-phenylenediamine film permits the one-step and all-chemical construction of a lactate amperometric biosensor. The sensor was prepared in situ i.e. in the flow injection analysis (FIA) system by simply injecting a plug of a solution containing the monomer and the enzyme. At a flow rate of 50 microL/min linearity was observed up to 0.2 mM lactate and detection limits of about 2 microM could be easily achieved. Faradaic interferences caused by ascorbate, urate, cysteine and acetaminophen were sufficiently minimized to permit lactate determination in diluted serum by FIA. Results obtained by FIA-amperometric detection compared well (according to a proper t-test at a 95% confidence level) with those obtained by a standard enzymatic colorimetric assay. At a flow rate of 1 ml/min a sample throughput higher than 70 sample h-1 was achieved. After one week of continuous use in the FIA system a 75% decrease in biosensor sensitivity was observed.
Palmisano
F
F
Dipartimento di Chimica, Universitá degli Studi, Bari, Italy.
Centonze
D
D
Zambonin
P G
PG
D000818:Animals; D015374:Biosensing Techniques; D004563:Electrochemistry; D004800:Enzymes, Immobilized; D017022:Flow Injection Analysis; D007773:Lactates / Q000097:blood*; D019344:Lactic Acid; D006899:Mixed Function Oxygenases; D051381:Rats
D004800:Enzymes, Immobilized; D007773:Lactates; D019344:Lactic Acid; D006899:Mixed Function Oxygenases; C021497:lactate 2-monooxygenase