Surface potential switching by metal ion complexation/decomplexation using bipyridinethiolate monolayers on gold

Tohru Nakamura, Emiko Koyama, Yukihiro Shimoi, Shuji Abe, Takao Ishida, Kiyomi Tsukagoshi, Wataru Mizutani, Hideo Tokuhisa, Masatoshi Kanesato, Ikuyo Nakai, Hiroshi Kondoh, Toshiaki Ohta

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14 Citations (Scopus)


Surface potential switching on gold(111) surfaces is induced by complexation/decomplexation reactions of a bipyridine (BP) derivative and palladium(II) chloride, as observed by Kelvin probe force microscopy (KFM). On the basis of the theoretical predictions, a 4-(5-phenylethynyl-2,2′- bipyridine-5′-yl-ethynyl)benzenethiol (PhBP) derivative was synthesized and used as an active monolayer to catch transition metal ions. By using the microcontact printing (CP) technique, micron-size patterned PhBP monolayers, which act as effective hosts to coordinate palladium(II) chloride, were prepared on gold(111) surfaces. The KFM signal decreases by complexation of the Pd(II) chloride in PhBP monolayers and is recovered by removal of Pd ions using an ethylenediamine solution, as confirmed by X-ray photoelectron spectroscopy. This process is reversible, indicating that the surface potential switching is realized by complexation/decomplexation of Pd(K). A CP PhBP monolayer, when it detects the target palladium ion, shows sensitivity for the picomolar level detection judged from surface potential changes in KFM measurements. The dipole moment estimated by the surface potentials is much smaller than the calculated value, indicating that mechanisms for the reduction of the surface dipole moment exist in real monolayers prepared by the CP method.

Original languageEnglish
Pages (from-to)9195-9203
Number of pages9
JournalJournal of Physical Chemistry B
Issue number18
Publication statusPublished - 2006 May 11
Externally publishedYes

ASJC Scopus subject areas

  • Physical and Theoretical Chemistry
  • Surfaces, Coatings and Films
  • Materials Chemistry


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