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Surface potential switching by metal ion complexation/decomplexation using bipyridinethiolate monolayers on gold
Tohru Nakamura1, Emiko Koyama, Yukihiro Shimoi
1Nanotechnology Research Institute (NRI), National Institute of Advanced Industrial Science and Technology (AIST), 1-1-1 Higashi, Tsukuba, Ibaraki 305-8565, Japan. tohru.nakamura@aist.go.jp
The Journal of Physical Chemistry. B
|May 5, 2006
Summary
This study demonstrates reversible surface potential switching on gold surfaces using a bipyridine derivative and palladium ions. This finding enables sensitive, picomolar-level detection of palladium, crucial for sensor development.
Area of Science:
- Surface science
- Nanotechnology
- Analytical chemistry
Background:
- Surface potential manipulation is key for advanced electronic devices.
- Developing sensitive methods for detecting metal ions is crucial in environmental and biomedical fields.
- Bipyridine derivatives offer versatile platforms for molecular recognition and surface functionalization.
Purpose of the Study:
- To investigate surface potential switching on gold(111) surfaces.
- To develop a patterned monolayer for selective metal ion detection.
- To demonstrate reversible complexation/decomplexation for sensing applications.
Main Methods:
- Synthesis of a 4-(5-phenylethynyl-2,2'-bipyridine-5'-yl-ethynyl)benzenethiol (PhBP) derivative.
- Microcontact printing (CP) to create patterned PhBP monolayers on gold(111).
- Kelvin probe force microscopy (KFM) for surface potential measurements and X-ray photoelectron spectroscopy (XPS) for chemical analysis.
Main Results:
- CP patterned PhBP monolayers effectively coordinate palladium(II) chloride.
- Palladium(II) complexation leads to a decrease in KFM signal, which is reversible upon ion removal.
- The system exhibits sensitivity down to the picomolar level for palladium ion detection.
Conclusions:
- Reversible surface potential switching is achieved through palladium ion complexation/decomplexation with PhBP monolayers.
- The developed method offers a sensitive platform for picomolar-level palladium detection.
- Discrepancies between estimated and calculated dipole moments suggest further investigation into monolayer behavior.