薄膜铂金宏观和微电极的电化学粗加工
Summary
该协议演示了一种在晶粒边界上不优先溶解的薄膜铂电极电化学粗加工方法。介绍了循环伏抗和阻抗光谱的电化学技术,以表征这些电极表面。
Abstract
该协议演示了一种在金属晶粒边界上不优先溶解薄膜铂电极电化学粗加工的方法。该方法得到一种无裂纹的薄膜大电极表面,有源表面积增加40倍。在标准电化学表征实验室中,粗加工很容易进行,并引入电压脉冲的应用,随后在高氯酸溶液中扩展应用还原电压。该协议包括宏观尺度(1.2 mm直径)和微尺度(20微米直径)铂盘电极表面的化学和电化学制备,对电极表面进行粗加工,并描述表面粗加工对电极有源表面积。这种电化学表征包括循环伏抗和阻抗光谱,并针对宏电极和微电极进行了演示。粗加工可增加电极有源表面积,降低电极阻抗,增加相同几何形状的氮化钛电极的铂电荷注入极限,并改进基板,使其附着电化学沉积薄膜.
Introduction
近五十年前,首次观测到表面增强拉曼光谱(SERS)发生在电化学粗化银1。金属箔的电化学粗加工今天仍然具有吸引力,因为它比其他粗加工方法2,3的简单性,它在许多应用中的有用性,如改进aptamer传感器4,改善神经探针5,提高金属基板6的附着力。许多散装金属的电化学粗加工方法存在1、5、7、8、9、10。然而,直到最近,还没有关于电化学粗加工应用于薄(百纳米厚)金属薄膜的报告,尽管微制薄膜金属电极在很多领域普遍存在。
建立的方法粗糙厚铂(Pt)电极5,8分层薄膜Pt电极6。通过调节粗加工过程的频率和用于粗加工的电解质,Ivanovskaya 等人演示了 Pt 薄膜粗加工,无需分层。该出版物侧重于使用这种新方法增加微制神经探头上铂记录和刺激电极的表面面积。该电极的粗加工性能提高了记录和刺激性能,提高了电化学沉积膜的附着力,提高了生物传感器的灵敏度6.但是,这种方法还可能改进微制电极阵列的表面清洁,并增强薄膜电极用于其他传感器应用(例如 aptasensor)的能力。
在以下协议中描述了粗制薄膜宏电极(1.2 mm直径)和微电极(20μm直径)的方法。这包括为粗加工而制备电极表面,以及如何描述电极的粗糙度。介绍了这些步骤,并介绍了如何针对其他电极几何形状优化粗加工过程以及确保电极无损粗加工的最重要因素。
Protocol
Representative Results
Discussion
薄膜大电极和微电极的电化学粗加工可以通过氧化还原脉冲进行。这种简单的方法确实需要几个关键元素来无损粗糙薄膜电极。与铝箔不同,如果参数没有正确选择,薄膜的粗加工可能导致样品破坏。粗加工过程的关键参数是脉冲振幅、持续时间和频率。此外,确保电极清洁度和在手术前的高氯酸纯度对于防止电极损坏至关重要。微加工过程中存在有机物或污染物,会通过腐蚀或分层造成电极的破坏。…
Divulgations
The authors have nothing to disclose.
Acknowledgements
作者感谢劳伦斯·利弗莫尔国家实验室生物工程中心在编写本手稿期间给予的支持。Loren Frank 教授因与团队合作,使上述工作中讨论的薄膜 Pt 微阵列的制造和设计得以进行,这一合作令人欣然接受。这项工作由美国能源部主持,由劳伦斯利弗莫尔国家实验室根据DE-AC52-07NA27344合同进行,并由实验室定向研发奖16-ERD-035资助。LLNL IM 版本 LLNL-JRNL-762701。
Materials
| Acetone | Fisher Scientific, Sigma Aldrich or similar | n/a | Laboratory grade |
| EC-Lab Software | Bio-Logic Science Instruments | n/a | For instrument control and data analysis |
| Leakless Silver/Silver Chloride Reference | eDAQ Company, Australia | ET069-1 | Free from chloride anion contamination (or other type of chloride free electrode e.g. Mercury sulfate electrode) |
| Mercury Sulfate & Acid Electrode Kit | Koslow, Scientific Testing Instruments | 5100A | glass, 9mm version |
| Milipore DI water | MilliporeSigma | n/a | Certified resistivity of 18.2 MΩ.cm (at 25°C) |
| Perchloric acid, 99.9985% | Sigma Aldrich | 311421 | High Purity |
| Phosphate-buffered saline | Teknova | P4007 | 10mM PBS with 100mM NaCl, pH 7 or similar product from elsewhere |
| Platinum Wire Auxiliary Electrode (7.5 cm) | BASi | MW-1032 | Counter electrode |
| Pt macroelectrodes | Lawrence Livermore National Laboratory | n/a | 1.2 mm diameter, 250 nm thick Pt disc electrodes insulated in polyimide. More information in Reference 9. |
| Pt microelectrode arrays | Lawrence Livermore National Laboratory | n/a | 20 µm diameter 250 nM thick Pt disc electrodes insulated in polyimide. More information in Reference 9. |
| Sulfuric acid, 99.999% | Sigma Aldrich | 339741 | High Purity |
| UV & Ozone Dry Stripper | Samco | UV-1 | for cleaning electrodes |
| VersaSTAT 4 Potentiostat | AMETEK, Inc. | n/a | Good time resolution for pulsing tests |
| VersaStudio Software | AMETEK, Inc. | n/a | For instrument control |
| VMP-200 Potentiostat | Bio-Logic Science Instruments | n/a | Low current resolution option is preferable for measurements with microelectrodes |
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