scholarly journals Cytochrome C as a benchmark system for a two-layer gold surface with improved surface-enhancement for spectro-electrochemistry

2010 ◽  
Vol 24 (1-2) ◽  
pp. 173-176 ◽  
Author(s):  
Christoph Nowak ◽  
Denise Schach ◽  
Marc Grosserüschkamp ◽  
Wolfgang Knoll ◽  
Renate L.C. Naumann
Keyword(s):  
Cytochrome C ◽  
Electroless Deposition ◽  
Au Nanoparticles ◽  
Gold Surface ◽  
Growth Conditions ◽  
Optimum Conditions ◽  
Self Assembled Monolayer ◽  
Surface Enhanced ◽  
Benchmark System ◽  
Reversible Reduction

A two-layer gold surface is developed for use with electrochemistry followed by surface-enhanced infrared absorption spectroscopy (SEIRAS) consisting of a conducting underlayer onto which Au nanoparticles (AuNPs) are grown by self-catalyzed electroless deposition. AuNPs are grown on protruding substructures of the 25 nm thin underlayer. The enhancement factor of the two-layer gold surface is controlled by the growth conditions. Cytochrome c adsorbed to a self-assembled monolayer of mercaptoethanol is used as a benchmark system for the investigation of complex heme proteins from the respiratory chain such as cytochrome c oxidase and the bc1 complex. Under optimum conditions the absorbance of the amide I band of cytochrome c is increased by a factor of 5 vs. classical SEIRAS surface. Reversible reduction/oxidation of cytochrome c on the two-layer gold surface is shown to take place by cyclic voltammetry.

A Two-Layer Gold Surface with Improved Surface Enhancement for Spectro-Electrochemistry Using Surface-Enhanced Infrared Absorption Spectroscopy

2009 ◽  
Vol 63 (9) ◽  
pp. 1068-1074 ◽  
Author(s):  
C. Nowak ◽  
C. Luening ◽  
W. Knoll ◽  
R. L. C. Naumann
Keyword(s):  
Cytochrome C ◽  
Absorption Spectroscopy ◽  
Infrared Absorption ◽  
Gold Surface ◽  
Growth Conditions ◽  
Infrared Absorption Spectroscopy ◽  
Optimum Conditions ◽  
Self Assembled Monolayer ◽  
Surface Enhanced ◽  
Reversible Reduction

A two-layer gold surface is developed for use with surface-enhanced infrared absorption spectroscopy (SEIRAS) consisting of a conducting underlayer onto which Au nanoparticles (AuNPs) are grown by self-catalyzed electroless deposition. AuNPs are grown on protruding substructures of the 25 nm thin underlayer. The enhancement factor of the two-layer gold surface is controlled by the growth conditions. Cytochrome c adsorbed to a self-assembled monolayer of mercaptoethanol is used as a reference system. Under optimum conditions the absorbance of the amide I band is increased by a factor of 5 versus the classical SEIRAS surface. Reversible reduction/oxidation of cytochrome c on the two-layer gold surface is shown to take place by cyclic voltammetry.

scholarly journals Molecular bridge-mediated ultralow-power gas sensing

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Aishwaryadev Banerjee ◽  
Shakir-Ul Haque Khan ◽  
Samuel Broadbent ◽  
Ashrafuzzaman Bulbul ◽  
Kyeong Heon Kim ◽  
...  
Keyword(s):  
Gas Sensing ◽  
Electron Tunneling ◽  
Gold Surface ◽  
Gold Electrodes ◽  
Self Assembled Monolayer ◽  
Output Resistance ◽  
Resistance Change ◽  
Ultralow Power ◽  
Linker Molecules ◽  
Molecular Bridge

AbstractWe report the electrical detection of captured gases through measurement of the quantum tunneling characteristics of gas-mediated molecular junctions formed across nanogaps. The gas-sensing nanogap device consists of a pair of vertically stacked gold electrodes separated by an insulating 6 nm spacer (~1.5 nm of sputtered α-Si and ~4.5 nm ALD SiO2), which is notched ~10 nm into the stack between the gold electrodes. The exposed gold surface is functionalized with a self-assembled monolayer (SAM) of conjugated thiol linker molecules. When the device is exposed to a target gas (1,5-diaminopentane), the SAM layer electrostatically captures the target gas molecules, forming a molecular bridge across the nanogap. The gas capture lowers the barrier potential for electron tunneling across the notched edge region, from ~5 eV to ~0.9 eV and establishes additional conducting paths for charge transport between the gold electrodes, leading to a substantial decrease in junction resistance. We demonstrated an output resistance change of >108 times upon exposure to 80 ppm diamine target gas as well as ultralow standby power consumption of <15 pW, confirming electron tunneling through molecular bridges for ultralow-power gas sensing.

scholarly journals Formation of HCN+ in collisions of N+ and N2+ with a self-assembled propanethiol surface on gold

2021 ◽  
Author(s):  
Faro Hechenberger ◽  
Siegfried Kollotzek ◽  
Lorenz Ballauf ◽  
Felix Duensing ◽  
Milan Ončák ◽  
...  
Keyword(s):  
Energy Range ◽  
Incident Energy ◽  
Gold Surface ◽  
Self Assembled Monolayer ◽  
Polycrystalline Gold ◽  
Self Assembled

Collisions of N+ and N2+ with C3 hydrocarbons, represented by a self assembled monolayer of propanethiol on a polycrystalline gold surface, were investigated by experiments over the incident energy range between 5 eV and 100 eV.

Surface-Enhanced Raman Scattering Dye-Labeled Au Nanoparticles for Triplexed Detection of Leukemia and Lymphoma Cells and SERS Flow Cytometry

Langmuir ◽  
2013 ◽  
Vol 29 (6) ◽  
pp. 1908-1919 ◽  
Author(s):  
Christina M. MacLaughlin ◽  
Nisa Mullaithilaga ◽  
Guisheng Yang ◽  
Shell Y. Ip ◽  
Chen Wang ◽  
...  
Keyword(s):  
Flow Cytometry ◽  
Raman Scattering ◽  
Au Nanoparticles ◽  
Surface Enhanced Raman Scattering ◽  
Lymphoma Cells ◽  
Surface Enhanced ◽  
Surface Enhanced Raman ◽  
Enhanced Raman Scattering
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