scholarly journals Nanoporous gold electrodes modified with self-assembled monolayers for electrochemical control of the surface charge

2021 ◽  
Author(s):  
Elisabeth Hengge ◽  
Markus Hirber ◽  
Philipp Brunner ◽  
Eva-Maria Steyskal ◽  
Bernd Nidetzky ◽  
...  
Keyword(s):  
Surface Charge ◽  
Nanoporous Gold ◽  
Point Of Zero Charge ◽  
Self Assembled Monolayers ◽  
Charge Control ◽  
Assembled Monolayers ◽  
Deprotonation Reaction ◽  
Electrochemical Control ◽  
Self Assembled ◽  
Long Chain

Nanoporous gold is modified with self-assembled monolayers (SAMs) of different length. The point of zero charge and the protonation/deprotonation reaction are investigated revealing precise charge control for long-chain SAMs.

scholarly journals Adsorption and desorption of self-assembled L-cysteine monolayers on nanoporous gold monitored by in situ resistometry

2019 ◽  
Vol 10 ◽  
pp. 2275-2279
Author(s):  
Elisabeth Hengge ◽  
Eva-Maria Steyskal ◽  
Rupert Bachler ◽  
Alexander Dennig ◽  
Bernd Nidetzky ◽  
...  
Keyword(s):  
Gold Surface ◽  
Research Field ◽  
Nanoporous Gold ◽  
Self Assembled Monolayers ◽  
Initial Surface ◽  
Resistance Change ◽  
Adsorption And Desorption ◽  
Assembled Monolayers ◽  
Self Assembled

Surface modifications of nanoporous metals have become a highly attractive research field as they exhibit great potential for various applications, especially in biotechnology. Using self-assembled monolayers is one of the most promising approaches to modify a gold surface. However, only few techniques are capable of characterizing the formation of these monolayers on porous substrates. Here, we present a method to in situ monitor the adsorption and desorption of self-assembled monolayers on nanoporous gold by resistometry, using cysteine as example. During the adsorption an overall relative change in resistance of 18% is detected, which occurs in three distinct stages. First, the cysteine molecules are adsorbed on the outer surface. In the second stage, they are adsorbed on the internal surfaces and in the last stage the reordering accompanied by additional adsorption takes place. The successful binding of cysteine on the Au surface was confirmed by cyclic voltammetry, which showed a significant decrease of the double-layer capacitance. Also, the electrochemically controlled desorption of cysteine was monitored by concomitant in situ resistometry. From the desorption peak related to the (111) surface of the structure, which is associated with a resistance change of 4.8%, an initial surface coverage of 0.48 monolayers of cysteine could be estimated.

Ordering and defects in self-assembled monolayers on nanoporous gold

2016 ◽  
Vol 387 ◽  
pp. 503-512 ◽  
Author(s):  
Dipna A. Patel ◽  
Andrew M. Weller ◽  
Robert B. Chevalier ◽  
Constantine A. Karos ◽  
Elizabeth C. Landis
Keyword(s):  
Nanoporous Gold ◽  
Self Assembled Monolayers ◽  
Assembled Monolayers ◽  
Self Assembled

scholarly journals Kinetic Isotope Effect on Electron Transfer Rates Across Self-Assembled Monolayers: A Case for Quantum Effects

2019 ◽  
Author(s):  
Samir Chattopadhyay ◽  
Sabyasanchi Bandyopadhyay ◽  
Abhishek Dey
Keyword(s):  
Cyclic Voltammetry ◽  
Kinetic Isotope Effect ◽  
Substantial Contribution ◽  
Self Assembled Monolayers ◽  
Transfer Rates ◽  
Medium Chain Length ◽  
Kinetic Isotope ◽  
Assembled Monolayers ◽  
Self Assembled ◽  
Long Chain

Long range ET across several self-assembled mon-olayer (SAM) covered Au electrodes is investigated using protonated and deuterated thiols (RSH/RSD). The rate of tunneling is measured using both chronoamperometry and cyclic voltammetry and it shows a prominent KIE. The KIE is ~2 (normal) for medium chain length thiols where the Tafel plot indicate substantial through space tunneling and is ~0.25 (inverse) for long chain thiols where the Tafel plot indicate mostly through bond tunneling. These results imply substantial contribution from the classical modes at the Au-(H)SR interface, which shift substantially on deuteration of the thiols, to the ET process.<br>

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