Determination of heavy metal toxicity by using a micro-droplet hydrodynamic voltammetry for microalgal bioassay based on alkaline phosphatase
Determination of heavy metal toxicity by using a micro-droplet hydrodynamic voltammetry for microalgal bioassay based on alkaline phosphatase
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DOI：
10.1016/j.chemosphere.2017.09.008
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发表时间：
2017-12-01
期刊：
影响因子：
8.8
通讯作者：
Kuramitz, Hideki
中科院分区：
文献类型：
--
作者：
Islam, Md. Saiful;Sazawa, Kazuto;Kuramitz, Hideki
基于莱茵衣藻对碱性磷酸酶（ALP）酶的抑制作用，建立了测定水中重金属毒性的电化学微藻生物测定法。五种重金属被选为有毒物质：汞、镉、铅、锌和铜。采用磷酸盐饥饿法抑制了C reinhardtii诱导的ALP活性，并通过对氨基酚（PAP）作为底物转化对氨基酚（PAPP）的电化学氧化来评价结果。采用旋转圆盘电极（RDE），采用流体动力学伏安法对50 μ l微滴的酶活性进行了快速测定。PAPP底物上的酶活性受到重金属离子的影响，这种现象降低了计时电流信号。ALP活性为对照（EC50）一半的Hg、Cd、Pb、Zn和Cu浓度分别为0.017、0.021、0.27、1.30和136。RDE系统被证明能够通过使用少量试剂检测酶活性，反应时间仅为60 s，检测限为5.4 x 10(-7) u (C) 2017 Elsevier Ltd.。版权所有。
We developed an electrochemical microalgal bioassay for the determination of heavy metal toxicity in water on the basis of the alkaline phosphatase (ALP) enzyme inhibition of Chlamydomonas reinhardtii. Five heavy metals were chosen as toxicants: Hg, Cd, Pb, Zn, and Cu. The induced ALP activity of C reinhardtii was inhibited using the phosphate starvation method, and the results were evaluated by measuring the electrochemical oxidation of p-aminophenol (PAP) following the enzymatic conversion of p-aminophenyl phosphate (PAPP) as a substrate. The rapid determination,of enzymatic activity was achieved using hydrodynamic voltammetry in a 50 mu L. micro-droplet with a rotating disk electrode (RDE). Enzymatic activity over a PAPP substrate is affected by heavy metal ions, and this phenomenon decreases the chronoamperometric current signal. The concentrations of Hg, Cd, Pb, Zn, and Cu in which the ALP activity was half that of the control (EC50) were found to be 0.017, 0.021, 0.27, 1.30, and 136 respectively. The RDE system was demonstrated to be capable of detecting enzymatic activity by using a small amount of regent, a reaction time of only 60 s, and a detection limit of 5.4 x 10(-7) U. (C) 2017 Elsevier Ltd. All rights reserved.