Electroreflectance Study of Gold Nanoparticles Immobilized on an Aminoalkanethiol Monolayer Coated on a Polycrystalline Gold Electrode Surface

2002 ◽  
Vol 106 (6) ◽  
pp. 1205-1212 ◽  
Author(s):  
Takamasa Sagara ◽  
Naoyuki Kato ◽  
Naotoshi Nakashima
Keyword(s):  
Gold Nanoparticles ◽  
Electrode Surface ◽  
Gold Electrode ◽  
Polycrystalline Gold

In situ IR spectroscopic study of water at a polycrystalline gold electrode surface

1998 ◽  
Vol 452 (2) ◽  
pp. 241-249 ◽  
Author(s):  
Fusao Kitamura ◽  
Noritoshi Nanbu ◽  
Takeo Ohsaka ◽  
Koichi Tokuda
Keyword(s):  
Spectroscopic Study ◽  
Electrode Surface ◽  
Gold Electrode ◽  
In Situ Ir ◽  
Polycrystalline Gold ◽  
Ir Spectroscopic

scholarly journals The Effect of Multilayer Gold Nanoparticles on the Electrochemical Response of Ammonium Ion Biosensor Based on Alanine Dehydrogenase Enzyme

2011 ◽  
Vol 2011 ◽  
pp. 1-8 ◽  
Author(s):  
Tan Ling Ling ◽  
Musa Ahmad ◽  
Lee Yook Heng ◽  
Toh Chee Seng
Keyword(s):  
Gold Nanoparticles ◽  
Electrode Surface ◽  
Linear Response ◽  
Gold Electrode ◽  
Thiol Group ◽  
Ion Concentration ◽  
Ammonium Ion ◽  
Current Response ◽  
Alanine Dehydrogenase ◽  
Response Range

The use of multilayer of gold nanoparticles (AuNPs) attached on gold electrode surface via thiol chemistry to fabricate an ammonium (NH4+) ion biosensor based on alanine dehydrogenase (AlaDH) was investigated. The approach of the study was based on construction of biosensor by direct deposition of AuNPs and 1,8-octanedithiol (C8-DT) onto the gold electrode surface. For the immobilisation of enzyme, 2-mercaptoethanol (2BME) was first covalently attached to AlaDH via esther bonding and then followed by chemically attached the 2BME-modified AlaDH (2BME-AlaDH) moiety onto the AuNPs electrode via the exposed thiol group of 2BME. The resulting biosensor response was examined by means of amperometry for the quantification ofNH4+ion. In the absence of enzyme attachment, the use of three layers of AuNPs was found to improve the electrochemistry of the gold electrode when compared with no AuNPs was coated. However, when more than three layers of AuNPs were coated, the electrode response deteriorated due to excessive deposition of C8-DT. When AlaDH was incoporated into the AuNPs modified electrode, a linear response toNH4+ion over the concentration range of 0.1–0.5 mM with a detection limit of 0.01 mM was obtained. In the absence of AuNPs, theNH4+ion biosensor did not exhibit any good linear response range although the current response was observed to be higher. This work demonstrated that the incorporation of AuNPs could lead to the detection of higherNH4+ion concentration without the need of dilution for highNH4+ion concentration samples with a rapid response time of <1 min.

Interaction of nitric oxide with Ru(II) complexes of deuteroporphyrindimethylester derivatives

2009 ◽  
Vol 13 (01) ◽  
pp. 35-40 ◽  
Author(s):  
Rudy Martin ◽  
Roberto Cao ◽  
Ana M. Esteva ◽  
Franz-Peter Montforts
Keyword(s):  
Nitric Oxide ◽  
Photoelectron Spectroscopy ◽  
Gold Electrode ◽  
Charge Transfer Band ◽  
Bathochromic Shift ◽  
Considerable Change ◽  
Cathodic Peak ◽  
X Ray ◽  
Polycrystalline Gold ◽  
Self Assembled

A new ruthenium(II) porphyrin disulphide derivative, [ Ru ( Pds )( CO )], was obtained from ruthenium(II)(carbonyl)deuteroporphyrin(IX), [ Ru ( DPdc )( CO )] and cystamine. The interaction of this complex with nitric oxide was studied spectrophotometrically and a bathochromic shift of the charge transfer band and considerable change in the α and β bands of the complex were observed. According to the IR spectrum, the product of this interaction is [ Ru ( DmDP )( NO +)( NO 2-)]. [ Ru ( Pds )( CO )] was then self-assembled on polycrystalline gold and characterized by X-ray photoelectron spectroscopy. [ Ru ( Pds )( CO )] was also self-assembled on gold electrode beads and its interaction with nitric oxide in aqueous solution was studied by cyclic voltammetry. A shift in the ruthenium redox process and a new irreversible cathodic peak at -0.59 V were observed, both indicating coordination of NO .

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