title: Amperometric bienzymatic biosensor for L-lactate analysis in wine and beer samples.
abstract: A novel amperometric bienzymatic biosensor has been developed based on the incorporation of Lactate Oxidase (LOx) and Horseradish Peroxidase (HRP) into a carbon nanotube/polysulfone membrane by the phase inversion technique onto screen-printed electrodes (SPEs). In order to improve the sensitivity and reduce the working potential, experimental conditions have been optimized and ferrocene has also been incorporated into the membrane as a redox mediator of the enzymatic reactions, which allows the reduction of H(2)O(2) at -100 mV. Measurements were carried out in phosphate buffer solution at pH 7.5 and under batch conditions. The biosensor response time to L-lactate was only 20 s and showed a good reproducibility (RSD 2.7%). Moreover, the detection limit was 0.05 mg L(-1) of l-lactate with a linear interval range from 0.1 mg L(-1) to 5 mg L(-1). Finally, the biosensor has been applied to the determination of l-lactic acid in different wine and beer samples. Then, the results obtained with the biosensor were compared with the ones obtained using, as a reference method, a commercial kit based on spectrophotometric measurements, obtaining an excellent agreement between the results, validating our approach.
authors: Sensors and Biosensors Group, Department of Chemistry, Universitat Autònoma de Barcelona, Edifici Cn, 08193 Bellaterra, Barcelona, Spain.
authors: Sandra
authors: S
authors: Pérez
authors: Esteve
authors: E
authors: Fàbregas
mesh_terms: D000818:Animals; D001515:Beer / Q000032:analysis*; D015374:Biosensing Techniques / Q000379:methods*; D002021:Buffers; D002417:Cattle; D004563:Electrochemistry / Q000379:methods*; D006735:Horseradish Peroxidase / Q000737:chemistry / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D007773:Lactates / Q000032:analysis*; D016014:Linear Models; D008567:Membranes, Artificial; D006899:Mixed Function Oxygenases / Q000737:chemistry / Q000378:metabolism*; D037742:Nanotubes, Carbon / Q000737:chemistry; D010376:Pediococcus / Q000201:enzymology; D011108:Polymers / Q000737:chemistry; D013450:Sulfones / Q000737:chemistry; D014920:Wine / Q000032:analysis*
chemical_list: D002021:Buffers; D007773:Lactates; D008567:Membranes, Artificial; D037742:Nanotubes, Carbon; D011108:Polymers; D013450:Sulfones; C017662:polysulfone P 1700; D006899:Mixed Function Oxygenases; D006735:Horseradish Peroxidase; C021497:lactate 2-monooxygenase