An L‐Lactate Amperometric Enzyme Electrode Based on L‐Lactate Oxidase Immobilized in a Laponite Gel on a Glassy Carbon Electrode. Application to Dairy Products and Red Wine

Abstract

International audienc

An amperometric biosensor based on lactate oxidase immobilized in laponite–chitosan hydrogel on a glassy carbon electrode. Application to the analysis of l-lactate in food samples

“…We recorded CV experiments on electrodes prepared with 25 g of laponite, 20 g of LOx and 25, 50, 75 or 100 g of CHT in 0.1 M KCl + 5 mM K 3 [Fe(CN) 6 ] at potential sweep rates v in the range (0.010 ≤ v ≤ 0.300 V s −1 ) (not shown). In all cases, a linear response of peak current I p vs. v 1/2 was observed.…”

“…The methodology involved the deposition of an aqueous mixture of laponite, enzyme, and an oligosilasesquioxane octamer on an electrode surface. It was proved that the laponite-octamer modified LOx biosensor was very convenient for the determination of l-lactate in foods without analytical problems associated with common interferents, including ascorbic acid, AA [6]. However, sensibility and stability improvement, as well as biopolymers more enzymecompatible and easier to prepare than oligosilasesquioxane are desirable.…”

“…In a previous publication we reported for the first time the use of FcMe in LOx regeneration in an amperometric biosensor, showing evidence for its very good performance [6].…”

“…In the former case, hydrogen peroxide is produced, which is quantified by oxidation at potentials usually above 0.5 V. Artificial mediators usually require lower oxidation potentials which are desirable for avoiding possible interferences from other oxidizable compounds [6]. Artificial mediators such as derivatives of ferrocene [7][8][9], p-phenylenediamine [10], osmium redox polymers [11,12], indophenol [13] or indoaniline [8], have been widely used.…”

Development of a Carbon Paste Electrode for Lactate Detection Based on Meldola’s Blue Adsorbed on Silica Gel Modified with Niobium Oxide and Lactate Oxidase

“…In addition, when tested in a solution with a relative high concentration (10 mmol L À1 ) of lactate followed by a low one (1 mmol L À1 ), the biosensor presented a rapid response to dynamic changes in the lactate concentration and no memory effect was observed (data not shown). The linear response range, detection limit and especially the stability presented by the proposed biosensor are significantly better than most of the amperometric biosensors for lactate described in the literature [11,12,17,21,[57][58][59][60][61][62]. The reproducibility between different electrodes (n = 4) was also determined and the response of biosensor at the same lactate concentration (1 mM) was 0.25 AE 0.02 mA cm À2 .…”