Different strategies for L-malic acid monitoring in wine are presented in this paper. A bi-enzymatic sensor was described based on the coupling of L-malate dehydrogenase with NADHoxidase, while monoenzymatic systems were based either on L-malate dehydrogenase or malate-quinone oxidoreductase. The bienzymatic sensors showed sensitivities of 3.6 mA/M and a detection limit of 4.5 μM, while for the monoenzymatic sensors the sensitivity was 1.1 mA/M and the detection limit was 2.4 μM. The optimized biosensors were used for determination of L-malic acid in different samples of wines.
- Malate dehydrogenase
- Malate-quinone oxidoreductase