Scanning Electrochemical Microscopy
Scanning Electrochemical Microscopy - Related Videos
11:41
Scanning Electron Microscopy (SEM)
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2023
Source: Laboratory of Dr. Andrew J. Steckl — University of Cincinnati A scanning electron microscope, or SEM, is a powerful microscope that uses electrons to form an image. It allows for imaging of conductive samples at magnifications that cannot be achieved using traditional microscopes. Modern light microscopes can achieve a magnification of ~1,000X, while typical SEM can reach magnifications of more than 30,000X. Because the SEM doesn’t use light to create images, the resulting pictures it...
08:57
Focussed Ion Beam Milling and Scanning Electron Microscopy of Brain Tissue
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Cited by 105 •
2011
This protocol describes how resin embedded brain tissue can be prepared and imaged in the three dimensions in the focussed ion beam, scanning electron microscope.
07:39
Electrochemical Biosensing
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2023
Electrochemical biosensors detect the binding of a target molecule by sensing an oxidation-reduction event. These sensors paved the way for modern biosensing after the invention of the glucose biosensor. This video will introduce electrochemical biosensing, show the workings of the glucose biosensor, and discuss how electrochemical biosensors are used in cancer detection.
01:07
Scanning Electron Microscopy
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2023
A scanning electron microscope (SEM) is used to study the surface features of a sample by using an electron beam that scans the sample surface in a two-dimensional manner. Typically, areas between ~1 centimeter to 5 micrometers in width can be imaged. SEM can be used to image bacteria, viruses, tissues as well as larger samples like insects. Conventional SEM gives a magnification ranging from 20X to 30,000X and spatial resolution of 50 to 100 nanometers. Fundamental Principles Accelerated...
11:42
Fabrication of Gate-tunable Graphene Devices for Scanning Tunneling Microscopy Studies with Coulomb Impurities
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Cited by 14 •
2015
This paper details the fabrication process of a gate-tunable graphene device, decorated with Coulomb impurities for scanning tunneling microscopy studies. Mapping the spatially dependent electronic structure of graphene in the presence of charged impurities unveils the unique behavior of its relativistic charge carriers in response to a local Coulomb potential.
FAQs
SECM feedback signals reflect both probe–sample distance and local electrochemical reactivity. As the ultramicroelectrode moves across an immersed surface, redox reactions at the probe and sample alter the measured current. Interpreting changes therefore requires separating positional effects from chemical behavior. This relationship lets researchers associate localized current patterns with active, inactive, or differently reactive microscopic regions.
The movable ultramicroelectrode concentrates measurement at a microscopic region rather than requiring the entire sample surface to contribute uniformly. Its position can be changed relative to the sample while current is monitored, allowing local variations in chemical activity and electrochemical behavior to appear in the measurement. This localized approach connects microscale surface structure with electrochemical function.
Averaging behavior across an entire surface can obscure differences between microscopic regions. SECM instead reveals how current and redox feedback vary from location to location, helping distinguish areas with different chemical activity or electrochemical response. That capability is especially important when a catalyst, membrane, corroding material, or biological interface does not behave uniformly across its surface.
A sample is immersed in an electrolyte, and a movable ultramicroelectrode is positioned near its surface or interface. The probe is then moved across microscopic regions while current is measured. Researchers interpret the resulting feedback signals in relation to probe–sample distance and local reactivity, producing spatially resolved information about chemical activity and electrochemical behavior.
Probe–sample distance, local surface reactivity, and the presence of an electrolyte directly shape the measured current. Moving the ultramicroelectrode changes its position relative to the sample, while local redox behavior changes the feedback response. Maintaining a controlled relationship between probe location and the immersed sample is therefore essential for interpreting spatial variations.
Chemists use Scanning Electrochemical Microscopy when they need to connect microscopic structure with localized electrochemical function. Applications include characterizing catalysts, corrosion, membranes, and biological interfaces, as well as examining reaction kinetics. The technique can also support sensor design and materials development by showing where chemical activity or electrochemical behavior differs across a sample.