Miniaturized probe on polymer SU-8 with array of individually addressable microelectrodes for electrochemical analysis in neural and other biological tissues
Miniaturized probe on polymer SU-8 with array of individually addressable microelectrodes for electrochemical analysis in neural and other biological tissues
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DOI：
10.1007/s00216-021-03327-2
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发表时间：
2021-05-07
影响因子：
4.3
通讯作者：
Fritsch, Ingrid
中科院分区：
文献类型：
--
作者：
Lotfi Marchoubeh, Mahsa;Cobb, Samuel J.;Fritsch, Ingrid
SU-8 探针具有九个可单独寻址的金微带电极（100 μm 长，4 μm 宽，间隔 4 μm 间隙）阵列，通过光刻技术制造和表征，用于检测密闭空间中的低浓度化学物质和生物组织的体内研究。探针的柄（6毫米长、100微米宽、100微米厚）是柔性的，但具有足够的锋利度和刚性以插入软组织。激光微加工通过在空间上揭示下面的牺牲铝层来定义探针的几何形状，然后蚀刻该铝层以将探针从硅晶片上分离出来。荧光纳米珠的灌注表明，与碳纤维电极一样，探针插入大鼠大脑时不会产生明显的损伤，与插入的微透析探针造成的损伤相反。电极的单独寻址能力允许单个和多个电极激活。氧化还原循环是可能的，其中相邻电极充当发生器（氧化或还原分子）和收集器（起到相反作用）以放大小浓度的信号，而无需扣除背景。还可以获得有关电化学机制和动力学的信息。对于单独的发生器以及氧化还原循环过程中的发生器和收集器，氯化钾电解质中铁氰化钾的检测限分别为 2.19、1.25 和 2.08 μM，人工脑脊髓液中多巴胺的检测限分别为 1.94、1.08 和 5.66 μM。
An SU-8 probe with an array of nine, individually addressable gold microband electrodes (100 mu m long, 4 mu m wide, separated by 4-mu m gaps) was photolithographically fabricated and characterized for detection of low concentrations of chemicals in confined spaces and in vivo studies of biological tissues. The probe's shank (6 mm long, 100 mu m wide, 100 mu m thick) is flexible, but exhibits sufficient sharpness and rigidity to be inserted into soft tissue. Laser micromachining was used to define probe geometry by spatially revealing the underlying sacrificial aluminum layer, which was then etched to free the probes from a silicon wafer. Perfusion with fluorescent nanobeads showed that, like a carbon fiber electrode, the probe produced no noticeable damage when inserted into rat brain, in contrast to damage from an inserted microdialysis probe. The individual addressability of the electrodes allows single and multiple electrode activation. Redox cycling is possible, where adjacent electrodes serve as generators (that oxidize or reduce molecules) and collectors (that do the opposite) to amplify signals of small concentrations without background subtraction. Information about electrochemical mechanisms and kinetics may also be obtained. Detection limits for potassium ferricyanide in potassium chloride electrolyte of 2.19, 1.25, and 2.08 mu M and for dopamine in artificial cerebral spinal fluid of 1.94, 1.08, and 5.66 mu M for generators alone and for generators and collectors during redox cycling, respectively, were obtained.