Details

Autor(en) / Beteiligte

• Groni, Sihem
• Fave, Claire
• Schöllhorn, Bernd
• Chapus, Lionel
• Aubertin, Pierre
• Touzalin, Thomas
• Lucas, Ivan T.
• Joiret, Suzanne
• Courty, Alexa
• Maisonhaute, Emmanuel

Titel

Long range self-organisations of small metallic nanocrystals for SERS detection of electrochemical reactions

Ist Teil von

• Journal of electroanalytical chemistry (Lausanne, Switzerland), 2020-09, Vol.872, p.114322, Article 114322

Ort / Verlag

Amsterdam: Elsevier B.V

Erscheinungsjahr

2020

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• Gold electrodes were modified by silver and gold nanocrystals (NCs) that self-organize onto the surface. Their optical properties were explored by measuring electroreflectance spectra as a function of electrode potential. Below their oxidation potential, no shift of the reflectance maximum was observed for Ag NCs. This can be explained by a low interfacial capacitance resulting from the impossibility for the electrolyte to penetrate into the hydrophobic layer created by the NCs dodecanethiol ligands. Conversely, a non-monotonous evolution was observed with the electrode potential for oleylamine capped Au NCs. This behavior is suggesting a less dense hydrophobic layer, allowing significant electrolyte penetration. Next, electroactive compounds were adsorbed on the the Au NCs assemblies and characterized by Raman spectroelectrochemistry. In the first system displaying a single electron transfer with no coupled chemical reaction, only the spectrum intensity changed, because oxidation generated a Raman resonant radical cation. The second study considered 4-nitrothiophenol, for which up to 6 electrons and 6 protons may be transferred. In this case, the nitro band disappeared upon reduction, and the spectrum displayed typical features of the formed 4-aminothiophenol.