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Abstract：
A photoelectrochemical biosensor for malate was developed using an indium tin oxide (ITO) layer deposited on a poly(ethylene terephthalate) plastic sheet as a transparent electrode material for the immobilization of malate dehydrogenase together with CdTe quantum dots. Different approaches were compared for the construction of the bioactive layer; the highest response was achieved by depositing malate dehydrogenase together with CdTe nanoparticles and covering it with a Nafion/water (1:1) mixture. The amperometric signal of this biosensor was recorded during irradiation with a near-UV LED in the flow-through mode. The limit of detection was 0.28 mmol/L, which is adequate for analyzing malic acid levels in drinks such as white wines and fruit juices. The results confirm that the cheap ITO layer deposited on the plastic sheet after cutting into rectangular electrodes allows for the economic production of photoelectrochemical (bio)sensors. The combination of NAD+-dependent malate dehydrogenase with quantum dots was also compatible with such an ITO surface.
摘要：
使用沉积在聚（对苯二甲酸乙二醇酯）塑料片上的氧化铟锡（ITO）层作为透明电极材料，将苹果酸脱氢酶与CdTe量子点固定在一起，开发了苹果酸的光电化学生物传感器。比较了不同的方法来构建生物活性层；通过将苹果酸脱氢酶与CdTe纳米粒子一起沉积并用Nafion/水（1：1）混合物覆盖，可以获得最高的响应。在以流通模式用近UVLED照射期间记录该生物传感器的安培信号。检出限为0.28mmol/L,这足以分析饮料如白葡萄酒和果汁中的苹果酸水平。结果证实，在切成矩形电极后，沉积在塑料片上的廉价ITO层可以经济地生产光电化学（生物）传感器。NAD+依赖性苹果酸脱氢酶与量子点的组合也与这种ITO表面相容。
