Optical sensitivity of a microelectrode in contact with an electrolyte
Optical sensitivity of a microelectrode in contact with an electrolyte
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与电解质接触的微电极的光学灵敏度
DOI：
10.1016/j.snb.2006.11.001
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发表时间：
2007
影响因子：
8.4
通讯作者：
R. Imamura
中科院分区：
文献类型：
--
作者：
Takaaki Isoda;N. Takahara;H. Imanaga;Shinya Hashizume;R. Imamura
研究了安装在芯片上的微电极传感器检测光强度的特性。通过光刻方法构建梳状微电极，由树脂芯片上的10μm厚的Cu膜组成。制作了三个具有不同梳数的梳状电极；长度为：a=10mm（8个梳子）、a=5mm（4个梳子）和a=2.5mm（2个梳子）。在 LED 发出的 0–1.5×103lx 的白光照射下，将 1.0×10–4 至 1.0moll–1（2–10μL）的 NaCl 溶液涂在微电极上。然后通过测量电阻来评估光学灵敏度。研究了电极尺寸和传感器材料对光学灵敏度检测限的影响。当电解质溶液接触一对梳状电极的表面时，传感器对光强度的变化做出响应。当强光照射到与氯化钠溶液接触的微电极上时，电阻显着降低。相反，当弱光照射与氯化钠溶液接触的微电极时，电阻增加。当传感器尺寸或梳子数量增加时，电阻随着光强度的增加而显着降低。特别是，八梳微传感器在0-1.0×103lx范围内的弱光强度下表现出高响应能力。当电解液浓度恒定时，电阻也收敛于恒定值。在所有测试的各种上板（聚酰亚胺、硅橡胶、玻璃和PET薄膜）中，电阻值取决于厚度，与光照射的强度无关。各种材料对光强度没有影响。然而，对于由聚四氟乙烯、聚丙烯和聚偏氯乙烯制成的上板，传感器的电阻增加，当光强度高时电阻降低。这表明当光照射到金属传感器表面和电解质滴的边界表面上时发生偏振。在电解质浓度恒定的情况下，发现传感器表面的电荷分布随着光照射的强度而变化。这些结果清楚地表明，光敏性和离子敏感性以及离子层的形成受到覆盖材料选择的影响。我们应用微电极作为微阵列的光学检测器来测量亚甲基蓝等染料的浓度。我们测量了位于微阵列背面的四个微电极的电阻值以及光强度。亚甲基蓝溶液的浓度分别为 0、1.0×10–3、1.0×10–2 和 1.0×10–1wt%，并将每种溶液 50μL 应用于每个微阵列。上板材料是半透明的并且照射光可以穿过包括染料溶液的微阵列。穿透的光被每个微电极以及位于微阵列下方的光电传感器接收。在每个微阵列中，微电极的检测电压取决于样本颜色的深度。
A microelectrode sensor mounted on a chip was investigated regarding its properties for detecting optical intensity. Comb-like shaped microelectrodes were constructed by a photolithographic method and consisted of a Cu film of 10μm thickness on a resin chip. Three comb-like electrodes with varying comb numbers were fabricated; lengths were: a=10mm (8 combs), a=5mm (4 combs), and a=2.5mm (2 combs). NaCl solutions of 1.0×10–4to 1.0moll–1(2–10μL) were applied on the microelectrode under white light irradiation of 0–1.5×103lx emitted from an LED. Optical sensitivity was then evaluated by measuring the electrical resistance. The effects of electrode size and sensor material on the detection limits for optical sensitivity were investigated. The sensor responded to changes in light intensity when an electrolyte solution contacted the surface of a pair of comb-like electrodes. When a strong light was irradiated onto the microelectrode in contact with an NaCl solution, the electrical resistance markedly reduced. By contrast, when a weak light was irradiated on the microelectrode in contact with an NaCl solution, the electrical resistance increased. When the sensor size or the number of combs was increased, electrical resistance showed a marked decrease with increased light intensity. In particular, an eight-comb microsensor exhibited high responsiveness under weak light intensity within the range of 0–1.0×103lx. When the electrolyte concentration is constant, electrical resistance also converges to a constant value. In all the various upper boards tested (polyimide, silicon rubber, glass, and PET film), the resistance value depended on the thickness regardless of the intensity of light irradiation. The various materials showed no effect on light intensity. However, the electrical resistance of the sensor increased for upper boards made of Teflon, polypropylene, and polychlorovinylidene for which electrical resistance was reduced when light intensity was high. It is suggested that polarization occurs when light is irradiated onto a metal sensor surface and the boundary surface of an electrolyte droplet. In the presence of a constant electrolyte concentration, the charge distribution on the surface of the sensor was found to change in accordance with the intensity of light irradiation. These results clearly demonstrate that photosensitivity and ion sensitivity, as well as the formation of the ion layer, are influenced by the choice of the cover material. We applied a microelectrode as an optical detector for a microarray to measure the concentration of a dye such as methylene blue. We measured the electrical resistance values, as well as those of light intensity, of four microelectrodes located on the reverse side of a microarray. Methylene blue solution was prepared at concentrations of 0, 1.0×10–3, 1.0×10–2, and 1.0×10–1wt% and 50μL of each solution was applied to each of the microarrays. The upper board material was translucent and irradiated light could pass through the microarrays including the dye solution. The light that penetrated was received by each microelectrode, as well as a photosensor located under microarray. In each of the microarrays, the detection voltage of the microelectrode depended on the depth of the sample color.
影响因子：
2.9
作者：
D. Pan;R. Mathies
通讯作者：
D. Pan;R. Mathies
影响因子：
7.4
作者：
Xue, QF;Foret, F;Karger, BL
通讯作者：
Karger, BL