ElKaoutit Mohammed, Naranjo-Rodriguez Ignacio, Temsamani Khalid Riffi, Hernández-Artiga Maria P, Bellido-Milla Dolores, Cisneros Jose Luis Hidalgo-Hidalgo de
Departamento de Quimica Analitica, Facultad de Ciencias, Universidad de Cadiz, Apdo. 40, 11510 Puerto Real, Cadiz, Spain.
Departement de Chimie, Equipe de Recherche Electrochimie et Systèmes Interfaciaux. Faculté des Siences de Tétouan, Université Abdelmalek Essaâdi, B.P. 2121, M'Hannech II-93002, Tétouan, Morocco.
Food Chem. 2008 Oct 15;110(4):1019-24. doi: 10.1016/j.foodchem.2008.03.006. Epub 2008 Mar 10.
Three phenoloxidases based biosensors were successfully developed using as electrochemical transducer a new type of electrode recently developed by our group: the "Sonogel-Carbon electrode". The employed enzymes were Trametes versicolor laccase (Lac), Mushroom tyrosinase (Tyr), and Horseradish peroxidase (HRP). Immobilization step was accomplished by doping the electrode surface with a mixture of the individual enzyme and Nafion ion exchanger as additive-protective. The biosensor responses, optimized in beer real samples, were evaluated for five individual polyphenols. It was found that the developed biosensors were sensitive to nanomolar concentrations of the tested polyphenols. As example, the limit of detection, sensitivity, and response linear range for caffeic acid for Nafion-Lac/Sonogel-Carbon biosensor were 0.06μmolL(-1), 99.6nAμmol(-1)L, and 0.04-2μmolL(-1), respectively. The stability and reproducibility of the biosensors were evaluated by applying them directly to beer real samples. It has been demonstrated that the Nafion-Lac/Sonogel-Carbon system is the more stable with a relative standard deviation of 3.3% (n=10), maintaining 84% of its stable response for at least three weeks. Estimation of polyphenol index in eight lager beers and a comparison of the results with those obtained by a classical method was carried out.
利用我们团队最近开发的一种新型电极——“声凝胶-碳电极”作为电化学传感器，成功研制出三种基于酚氧化酶的生物传感器。所使用的酶分别是云芝漆酶（Lac）、蘑菇酪氨酸酶（Tyr）和辣根过氧化物酶（HRP）。通过将每种酶与作为添加剂-保护剂的Nafion离子交换剂的混合物掺杂在电极表面来完成固定化步骤。在啤酒实际样品中对生物传感器的响应进行了优化，并针对五种单独的多酚进行了评估。结果发现，所研制的生物传感器对测试多酚的纳摩尔浓度敏感。例如，Nafion-Lac/声凝胶-碳生物传感器对咖啡酸的检测限、灵敏度和响应线性范围分别为0.06μmolL(-1)、99.6nAμmol(-1)L和0.04 - 2μmolL(-1)。通过将生物传感器直接应用于啤酒实际样品来评估其稳定性和重现性。结果表明，Nafion-Lac/声凝胶-碳系统最为稳定，相对标准偏差为3.3%（n = 10），在至少三周内保持其稳定响应的84%。对八种贮藏啤酒中的多酚指数进行了估算，并将结果与通过经典方法获得的结果进行了比较。
