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Visualizing and Calculating Tip-Substrate Distance in Nanoscale Scanning Electrochemical Microscopy Using 3-Dimensional Super-Resolution Optical Imaging
- Source :
- Analytical chemistry. 89(1)
- Publication Year :
- 2016
-
Abstract
- We report a strategy for the optical determination of tip-substrate distance in nanoscale scanning electrochemical microscopy (SECM) using three-dimensional super-resolution fluorescence imaging. A phase mask is placed in the emission path of our dual SECM/optical microscope, generating a double helix point spread function at the image plane, which allows us to measure the height of emitting objects relative to the focus of the microscope. By exciting both a fluorogenic reaction at the nanoscale electrode tip as well as fluorescent nanoparticles at the substrate, we are able to calculate the tip-substrate distance as the tip approaches the surface with precision better than 25 nm. Attachment of a fluorescent particle to the insulating sheath of the SECM tip extends this technique to nonfluorogenic electrochemical reactions. Correlated electrochemical and optical determination of tip-substrate distance yielded excellent agreement between the two techniques. Not only does super-resolution imaging offer a secondary feedback mechanism for measuring the tip-sample gap during SECM experiments, it also enables facile tip alignment and a strategy for accounting for electrode tilt relative to the substrate.
- Subjects :
- Point spread function
Fluorescence-lifetime imaging microscopy
Microscope
business.industry
Chemistry
02 engineering and technology
Substrate (electronics)
010402 general chemistry
021001 nanoscience & nanotechnology
01 natural sciences
0104 chemical sciences
Analytical Chemistry
law.invention
Scanning electrochemical microscopy
Optics
Optical microscope
law
Electrode
0210 nano-technology
business
Nanoscopic scale
Subjects
Details
- ISSN :
- 15206882
- Volume :
- 89
- Issue :
- 1
- Database :
- OpenAIRE
- Journal :
- Analytical chemistry
- Accession number :
- edsair.doi.dedup.....a52ab3c461b2aa110ddcd2ae605b53be