查看“︁扫描电化学显微镜”︁的源代码

'''扫描电化学显微镜'''（{{lang-en|'''Scanning electrochemical microscopy'''}}，缩写'''SECM'''）基于[[电化学]]原理工作，利用驱动非常小的电极（探针）在靠近样品处进行扫描，样品可以是[[导体]]、[[绝缘体]]或[[半导体]]，可测量微区内物质氧化或还原所给出的电化学电流，进而确定界面上的电化学行为。<ref name="Unwin, 99', gas/liquid interface">{{cite journal|last=Unwin|first=Patrick |author2=Barker, Gonsalves |author3=Macpherson, Slevin|title=Scanning electrochemical microscopy: beyond the solid/liquid interface|year=1999|volume=385|pages=223–240}}</ref><ref name="Zhang, 01', liquid/liq">{{cite journal|last=Zhang|first=Jie|author2=Barker, Unwin |title=Measurement of the forward and back rate constants for electron transfer at the interface between two immiscible electrolyte solutions using scanning electrochemical microscopy (SECM): Theory and experiment|journal=Electrochemistry Communications|year=2001|volume=3|issue=7|pages=372–378|doi=10.1016/s1388-2481(01)00173-4}}</ref><ref name="Mirkin, 06', e transfer at nanoelectrodes">{{cite journal|last=Mirkin|first=Michael|author2=Sun |title=Kinetics of electron transfer reactions at nanoelectrodes|journal=Analytical Chemistry|year=2006|volume=78|issue=18|pages=6526–6534|doi=10.1021/ac060924q|pmid=16970330}}</ref><ref name="Mirkin, 07, Review">{{cite journal|last=Mirkin|first=Michael|author2=Peng Sun |author3=Francois O. Laforge |title=Scanning electrochemical microscopy in the 21st century|journal=Physical Chemistry Chemical Physics|year=2007|volume=9|issue=7|pages=802–823|doi=10.1039/b612259k|pmid=17287874|bibcode = 2007PCCP....9..802S }}</ref><ref name="Wittstock, 03, Review">{{cite journal|last=Wittstock|first=Gunther|title=Imaging Localized Reactivities of Surfaces by Scanning Electrochemical Microscopy|journal=Topics in Applied Physics|year=2003|volume=85|pages=335–366|doi=10.1007/3-540-44817-9_11|isbn=978-3-540-42583-0}}</ref>目前可达到的最高分辨率约为几十[[纳米]]。这一技术也可以被用于微观刻印和微结构的创造<ref name="Gorman, 03, Patterning Review">{{cite journal|last=Gorman|first=Christopher|author2=Stephan Kramer |author3=Ryan R. Fuierer |title=Scanning Probe Lithography Using Self-Assembled Monolayers|journal=Chemical Reviews|year=2003|volume=103|issue=11|pages=4367–4418|doi=10.1021/cr020704m|pmid=14611266}}</ref>

==历史==
1980年左右，超微电极的出现对于发展高敏感度电分析技术是关键的。将超微电极用作探针，就可以研究局部快速进行的电化学反应。1986年Engstrom进行了第一次类似扫描电化学显微镜的实验，观察到了反应情况和中间体。<ref name="Engstrom 1986">{{cite journal|last=Engstrom|first=R.C.|author2=M. Weber |author3=D. J. Wunder |author4=R. Burgess |author5=S. Winguist |title=Measurements within the diffusion layer using a microelectrode probe|journal=Anal. Chem.|date=April 1986|volume=58|issue=4|pages=844–848|doi=10.1021/ac00295a044}}</ref> 同时，阿兰·J·巴尔德通过分析法拉第电流导致的测量偏差，对电化学显微镜的原理进行了彻底的分析<ref name="Bard 1986">{{cite journal|last=Bard|first=Allen |author2=Hsue-Yang Liu |author3=Fu-Ren F. Fan |author4=Charles W. Lin|title=Scanning Electrochemical and Tunneling Ultramicroelectrode Microscope for High-Resolution Examination of Electrode Surfaces in Solution|journal=J. Am. Chem. Soc.|year=1986|volume=108|issue=13 |pages=3838–3839|doi=10.1021/ja00273a054}}</ref>1989年巴尔德正式建立了扫描电化学显微镜的理论原理，也创造了这个词汇。当时研究者采用的是收集模式，而巴尔德引入反馈模式，扩大了扫描电化学显微镜的应用范围。<ref name="Bard, 89', Seminal" />

随着理论基础的发展，1999年有关SECM的文献已经增加到了80篇，第一台商用的SECM也诞生了<ref name="Mirkin review SECM in 21s century 2006">{{cite journal|last=Mirkin|first=Michael|author2=Peng Sun|author3=Francois Laforge|title=Scanning electrochemical microscopy in the 21st century|journal=Physical Chemistry Chemical Physics|date=30 November 2006|volume=9|issue=7|pages=802–23|doi=10.1039/b612259k|pmid=17287874|url=http://www.rsc.org/pccp|accessdate=5 October 2011|bibcode=2007PCCP....9..802S|archive-date=2008-11-21|archive-url=https://web.archive.org/web/20081121140409/http://www.rsc.org/pccp|dead-url=no}}</ref>今日，扫描电化学显微镜的应用范围在扩大，精度也在提高，理论和技术上的研究仍在不断深入。<ref>{{cite journal | doi = 10.1039/c1cp22376c | volume=13 | title=Scanning electrochemical microscopy in the 21st century. Update 1: five years after | year=2011 | journal=Physical Chemistry Chemical Physics | last1 = Mirkin | first1 = Michael V. | last2 = Nogala | first2 = Wojciech | last3 = Velmurugan | first3 = Jeyavel | last4 = Wang | first4 = Yixian| issue=48 | pages=21196–21312 | pmid=22031463 | bibcode=2011PCCP...1321196M }}</ref>

==工作原理==
在含有氧化-还原对（如Fe<sup>2+</sup>/Fe<sup>3+</sup>）的溶液中放置超微电极，用于施加和改变电压。当足够的负电势被施加时，三价铁会被还原成二价铁，形成扩散控制的电流<ref name="Engstrom 1986"/> 稳态电流与氧化剂的流量的关系是：

<math>i_{T, \infty} = 4nFCDa</math>

此处 ''i<sub>T,∞</sub>''是扩散控制电流，''n''是电极上转移的电子数(O + ''n''e<sup>−</sup> → R), ''F''是[[法拉第常数]], ''C''是溶液中被氧化物质的浓度, ''D''是[[扩散系数]]而''a''是超微电极盘子的半径。为了扫描感兴趣的表面，探针需要接近表面，然后记录电流的变化。

现在有两种主要的工作原理，反馈模式和获取-产生模式

==参考文献==
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{{扫描探针显微镜}}
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[[category:顯微鏡]]
[[category:纳米技术]]
[[Category:电化学]]