A dual electrochemical microsensor for simultaneous imaging of oxygen and pH over the rat kidney surface
A dual electrochemical microsensor for simultaneous imaging of oxygen and pH over the rat kidney surface
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DOI：
10.1039/c3an00878a
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发表时间：
2013-01-01
期刊：
影响因子：
4.2
通讯作者：
Lee, Youngmi
中科院分区：
文献类型：
--
作者：
Ha, Yejin;Myung, Dongshin;Lee, Youngmi
在这项研究中，用于测量氧气（O-2）和pH值水平的双微传感电化学探针开发的基础上，双凹进铂盘电极（每个盘直径，10 mm）与使用两个Ag/AgCl参比电极（一个用于每个磁盘的双电极）。双电极的凹陷Pt盘之一电沉积有多孔Pt层，然后涂覆有疏水光固化聚合物（部分氟化环氧二丙烯酸酯，缩写为FED）。Pt-FED覆盖的盘用作电流型O-2传感器，并表现出与PO 2水平（O-2分压）成比例的线性电流增加，具有高灵敏度（168.4 +/- 33.8 pA mmHg（-1））和快速响应时间（t（90）% 0.17 +/- 0.05 s）。另一个凹进的Pt盘用IrO 2层电沉积。IrO 2沉积电极和Ag/AgCl参比电极之间的电位对pH变化产生可靠的能斯特响应（58.3 +/- 1.5 mV pH（-1）），t（90）%为0.43 +/- 0.09 s。该传感器在体外器官组织测量中显示出至少2.5 h的高稳定性。通过使用开发的双O-2/pH微传感器作为扫描电化学显微镜的探针尖端，二维图像的位置依赖的PO 2和pH值的水平同时获得，并可用于评估大鼠肾组织切片的表面。与相应的髓质水平相比，在皮质区观察到PO 2和pH值较高，而在皮质-髓质边界附近观察到适度的水平梯度。这一发现表明，组织O-2供应/消耗和pH值之间存在直接关系，这主要取决于代谢产物，如CO2，生产。
In this study, a dual microsensing electrochemical probe for measuring oxygen (O-2) and pH levels was developed based on a dual recessed Pt disk electrode (each disk diameter, 10 mm) with the use of two Ag/AgCl reference electrodes (one for each disk of the dual electrode). One of the recessed Pt disks of the dual electrode was electrodeposited with a porous Pt layer and then coated with a hydrophobic photocured polymer (partially fluorinated epoxy diacrylate, abbreviated as FED). The Pt-FED covered disk was used as an amperometric O-2 sensor and exhibited a linear current increase that was proportional to the PO2 level (partial O-2 pressure) with high sensitivity (168.4 +/- 33.8 pA mmHg(-1)) and fast response time (t(90)% 0.17 +/- 0.05 s). The other recessed Pt disk was electrodeposited with an IrO2 layer. The potential between the IrO2 deposited electrode and the Ag/AgCl reference electrode produced a reliable Nernstian response to pH changes (58.3 +/- 1.5 mV pH(-1)) with a t(90)% of 0.43 +/- 0.09 s. The sensor displayed high stability in the in vitro organ tissue measurements for at least 2.5 h. By using the developed dual O-2/pH microsensor as a probe tip for scanning electrochemical microscopy, the two-dimensional images of the location-dependent PO2 and pH levels were simultaneously acquired and could be used to assess the surface of a rat kidney tissue slice. When compared to the corresponding medullary levels, both PO2 and pH were observed to be higher in the cortex area, while the modest level gradient was observed near the cortex-medulla border. This finding suggests that there is a direct relationship between the tissue O-2 supply/consumption and pH, which is mainly determined by metabolite, such as CO2, production.