海岸带环境工程技术研究与发展中心知识库

(1) 中国科学院烟台海岸带研究所中国科学院海岸带环境过程与生态修复重点实验室

In this work,we constructed a novel microelectrode for stable pH monitoring for in-situ determination of plant tissues.The Ir was electrochemically modified by cyclic voltammetry under alkaline conditions to obtain a pH-type electrode of Ir/Ir(OH)_x.The morphology and electrochemical properties of electrodes were studied.The results show that a layer of white Ir(OH)_x film is formed on the surface of the electrochemically modified silk.The electrode is sensitive to pH and the potential and pH are Nernst linear response in the range of pH=4-10.The response time of the electrode is about 60 s,and the electrode has good stability by many times interval measuring.The in-situ measurement of the growth condition of the plant culture process was carried out by using the electrode.It was found that the pH of the Epipremnum aureum had slight decrease under cultivating in the hydroponic solution of the weak acid salt,and the stem of the plant showed a hysteresis trend compared with the rhizome.Therefore,the iridium needle electrode can be used to measure the in situ pH value of plant tissues.

构建能稳定检测pH的新型微电极,并用于植物组织的原位测定。在碱性条件下采用循环伏安法对Ir针进行电化学修饰,得到Ir/Ir(OH)_x型pH电极,并对该修饰电极的形貌及电化学性质进行了研究。裸Ir电极和Ir/Ir(OH)_x电极的对比扫描电镜(SEM)图显示,电化学修饰的Ir丝表面增加了一层白色Ir(OH)_x膜。Ir/Ir(OH)_x型电极对pH响应敏感,在pH=4~10范围内其电势与pH呈能斯特线性响应。电极的响应时间为60s左右,多次间隔测定,电极具有较好稳定性。利用该电极对植物培养过程的生长状况进行原位分析测定,发现在弱酸盐溶液水培下的绿萝(Epipremnum Aureum),随水培缓冲溶液的pH值微弱降低,且植物茎干较根茎表现出迟滞的变化趋势。将该Ir针电极应用于植物组织pH值原位测量,尤其对耐盐植物选育和根茎pH变化监测具有潜在应用价值。