Molecular Assembly and Electropolymerization of 3,4-Ethylenedioxythiophene on Au(111) Single Crystal Electrode as Probed by In Situ Electrochemical STM in 0.10 M HClO4

Langmuir ◽  
2010 ◽  
Vol 26 (13) ◽  
pp. 10771-10777 ◽  
Author(s):  
Lorico D. S. Lapitan ◽  
Bernard John V. Tongol ◽  
Shueh-Lin Yau
Keyword(s):  
Single Crystal ◽  
Molecular Assembly ◽  
Single Crystal Electrode

scholarly journals Voltammetry and molecular assembly of G-quadruplex DNAzyme on single-crystal Au(111)-electrode surfaces – hemin as an electrochemical intercalator

2016 ◽  
Vol 193 ◽  
pp. 99-112 ◽  
Author(s):  
Ling Zhang ◽  
Jens Ulstrup ◽  
Jingdong Zhang
Keyword(s):  
Single Crystal ◽  
Single Molecule ◽  
Electrode Surface ◽  
Molecular Assembly ◽  
Electrode Surfaces ◽  
Potential Control ◽  
G Quadruplex ◽  
Tunnelling Microscopy ◽  
Dna Quadruplexes

DNA quadruplexes (qs) are a class of “non-canonical” oligonucleotides (OGNs) composed of stacked guanine (G) quartets stabilized by specific cations. Metal porphyrins selectively bind to G-qs complexes to form what is known as DNAzyme, which can exhibit peroxidase and other catalytic activity similar to heme group metalloenzymes. In the present study we investigate the electrochemical properties and the structure of DNAzyme monolayers on single-crystal Au(111)-electrode surfaces using cyclic voltammetry and scanning tunnelling microscopy under electrochemical potential control (in situ STM). The target DNAzyme is formed from a single-strand OGN with 12 guanines and iron(iii) porphyrin IX (hemin), and assembles on Au(111) through a mercapto alkyl linker. The DNAzyme monolayers exhibit a strong pair of redox peaks at 0.0 V (NHE) at pH 7 in acetate buffer, shifted positively by about 50 mV compared to free hemin weakly physisorbed on the Au(111)-electrode surface. The voltammetric hemin signal of DNAzyme is enhanced 15 times compared with that of hemin adsorbed directly on the Au(111)-electrode surface. This is indicative of both the formation of a close to dense DNAzyme monolayer and that hemin is strongly bound to the immobilized 12G-qs in well-defined orientation favorable for interfacial ET with a rate constant of 6.0 ± 0.4 s−1. This is supported by in situ STM which discloses single-molecule G-quartet structures with a size of 1.6 ± 0.2 nm.

In Situ SHINERS at Electrochemical Single-Crystal Electrode/Electrolyte Interfaces: Tuning Preparation Strategies and Selected Applications

ACS Nano ◽  
2013 ◽  
Vol 7 (10) ◽  
pp. 8940-8952 ◽  
Author(s):  
Jian-Feng Li ◽  
Alexander Rudnev ◽  
Yongchun Fu ◽  
Nataraju Bodappa ◽  
Thomas Wandlowski
Keyword(s):  
Single Crystal ◽  
Single Crystal Electrode

An in-situ X-ray diffraction study on the electrochemical formation of PtZn alloys on Pt(1 1 1) single crystal electrode

2015 ◽  
Vol 354 ◽  
pp. 443-449 ◽  
Author(s):  
J. Drnec ◽  
D. Bizzotto ◽  
F. Carlà ◽  
R. Fiala ◽  
A. Sode ◽  
...  
Keyword(s):  
Single Crystal ◽  
Diffraction Study ◽  
X Ray Diffraction ◽  
X Ray ◽  
Single Crystal Electrode

Second harmonic generation study of the reconstruction of an Au(110) electrode in HClO4

1997 ◽  
Vol 75 (4) ◽  
pp. 449-455 ◽  
Author(s):  
C. Dale Keefe ◽  
Erika Revesz ◽  
Michel Dionne ◽  
Mario Morin
Keyword(s):  
Second Harmonic Generation ◽  
Single Crystal ◽  
Harmonic Generation ◽  
Second Harmonic ◽  
Large Component ◽  
In Situ Study ◽  
Threefold Symmetry ◽  
Single Crystal Electrode ◽  
Second Harmonic Generation Spectroscopy

Second harmonic generation (SHG) was used to carry out an in situ study of the potential-induced reconstruction of an Au(110) single crystal electrode in an aqueous solution of 0.01 M HClO4. In this study, we found that the symmetries of the surface susceptibility of the reconstructed and the unreconstructed Au(110) surfaces have a large component of threefold symmetry. A detailed analysis shows that both surfaces have an overall Cs symmetry giving one-, two-, and threefold symmetries for the surface susceptibility. However, another, different, source of threefold symmetry, perpendicular to the first, is needed to fit the data. We suggest that this extra source of threefold symmetry is due to the (111) microfacets that are present on the open (110) surface. Keywords: electrochemistry, single crystal, reconstruction, second harmonic generation spectroscopy.

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