Long-Range Interfacial Electrochemical Electron Transfer of Pseudomonas aeruginosa Azurin-Gold Nanoparticle Hybrid Systems

Palle Skovhus Jensen, Qijin Chi, Jingdong Zhang, Jens Ulstrup

Research output: Contribution to journalJournal articleResearchpeer-review

Abstract

We have prepared a "hybrid" of the blue copper protein azurin (Pseudomonas aeruginosa) and a 3 nm gold nanoparticle (AuNP). The AuNP/azurin hybrid was assembled on a Au(111)-electrode surface in a two-step process. The AuNP was first attached to the Au(111) electrode via Au-S chemisorption of a 4,4'-biphenyidithiol (4,4'-BPDT) monolayer. This was followed by 1-decanethiol modification of the bound AuNP and hydrophobic binding of azurin to the AuNP. The Au(111)/AuNP/azurin system was characterized by atomic force microscopy (AFM), cyclic voltammetry (CV), and in situ electrochemical scanning tunneling microscopy (in situ STM). AFM and STM point to the feasibility of preparing both dense and sparsely populated AuNP monolayers. CV shows two pairs of voltammetric peaks at high scan rates, both around the azurin equilibrium potential. One pair of redox peaks follows closely that of azurin hydrophobically immobilized directly on a Au(111)/1-tetradecanethiol reference surface. The other pair, tentatively assigned to the AuNP/azurin hybrid, shows a 20-fold electron transfer rate enhancement over the reference system. This dual pattern is supported by in situ STM which shows two distinct contrasts. A strong contrast most likely arises either from azurin-free AuNPs or from AuNP-free azurin displaced onto the Au(111)/4,4'-BPDT surface. The other contrast, assigned to the AuNP/azurin hybrid, is weaker and fluctuates in time. Mechanisms of electronic conductivity of the AuNP/azurin system are discussed.
Original languageEnglish
JournalJournal of Physical Chemistry Part C: Nanomaterials and Interfaces
Volume113
Issue number31
Pages (from-to)13993-14000
ISSN1932-7447
DOIs
Publication statusPublished - 2009

Cite this

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title = "Long-Range Interfacial Electrochemical Electron Transfer of Pseudomonas aeruginosa Azurin-Gold Nanoparticle Hybrid Systems",
abstract = "We have prepared a {"}hybrid{"} of the blue copper protein azurin (Pseudomonas aeruginosa) and a 3 nm gold nanoparticle (AuNP). The AuNP/azurin hybrid was assembled on a Au(111)-electrode surface in a two-step process. The AuNP was first attached to the Au(111) electrode via Au-S chemisorption of a 4,4'-biphenyidithiol (4,4'-BPDT) monolayer. This was followed by 1-decanethiol modification of the bound AuNP and hydrophobic binding of azurin to the AuNP. The Au(111)/AuNP/azurin system was characterized by atomic force microscopy (AFM), cyclic voltammetry (CV), and in situ electrochemical scanning tunneling microscopy (in situ STM). AFM and STM point to the feasibility of preparing both dense and sparsely populated AuNP monolayers. CV shows two pairs of voltammetric peaks at high scan rates, both around the azurin equilibrium potential. One pair of redox peaks follows closely that of azurin hydrophobically immobilized directly on a Au(111)/1-tetradecanethiol reference surface. The other pair, tentatively assigned to the AuNP/azurin hybrid, shows a 20-fold electron transfer rate enhancement over the reference system. This dual pattern is supported by in situ STM which shows two distinct contrasts. A strong contrast most likely arises either from azurin-free AuNPs or from AuNP-free azurin displaced onto the Au(111)/4,4'-BPDT surface. The other contrast, assigned to the AuNP/azurin hybrid, is weaker and fluctuates in time. Mechanisms of electronic conductivity of the AuNP/azurin system are discussed.",
author = "Jensen, {Palle Skovhus} and Qijin Chi and Jingdong Zhang and Jens Ulstrup",
year = "2009",
doi = "10.1021/jp902611x",
language = "English",
volume = "113",
pages = "13993--14000",
journal = "The Journal of Physical Chemistry Part C",
issn = "1932-7447",
publisher = "American Chemical Society",
number = "31",

}

Long-Range Interfacial Electrochemical Electron Transfer of Pseudomonas aeruginosa Azurin-Gold Nanoparticle Hybrid Systems. / Jensen, Palle Skovhus; Chi, Qijin; Zhang, Jingdong; Ulstrup, Jens.

In: Journal of Physical Chemistry Part C: Nanomaterials and Interfaces, Vol. 113, No. 31, 2009, p. 13993-14000.

Research output: Contribution to journalJournal articleResearchpeer-review

TY - JOUR

T1 - Long-Range Interfacial Electrochemical Electron Transfer of Pseudomonas aeruginosa Azurin-Gold Nanoparticle Hybrid Systems

AU - Jensen, Palle Skovhus

AU - Chi, Qijin

AU - Zhang, Jingdong

AU - Ulstrup, Jens

PY - 2009

Y1 - 2009

N2 - We have prepared a "hybrid" of the blue copper protein azurin (Pseudomonas aeruginosa) and a 3 nm gold nanoparticle (AuNP). The AuNP/azurin hybrid was assembled on a Au(111)-electrode surface in a two-step process. The AuNP was first attached to the Au(111) electrode via Au-S chemisorption of a 4,4'-biphenyidithiol (4,4'-BPDT) monolayer. This was followed by 1-decanethiol modification of the bound AuNP and hydrophobic binding of azurin to the AuNP. The Au(111)/AuNP/azurin system was characterized by atomic force microscopy (AFM), cyclic voltammetry (CV), and in situ electrochemical scanning tunneling microscopy (in situ STM). AFM and STM point to the feasibility of preparing both dense and sparsely populated AuNP monolayers. CV shows two pairs of voltammetric peaks at high scan rates, both around the azurin equilibrium potential. One pair of redox peaks follows closely that of azurin hydrophobically immobilized directly on a Au(111)/1-tetradecanethiol reference surface. The other pair, tentatively assigned to the AuNP/azurin hybrid, shows a 20-fold electron transfer rate enhancement over the reference system. This dual pattern is supported by in situ STM which shows two distinct contrasts. A strong contrast most likely arises either from azurin-free AuNPs or from AuNP-free azurin displaced onto the Au(111)/4,4'-BPDT surface. The other contrast, assigned to the AuNP/azurin hybrid, is weaker and fluctuates in time. Mechanisms of electronic conductivity of the AuNP/azurin system are discussed.

AB - We have prepared a "hybrid" of the blue copper protein azurin (Pseudomonas aeruginosa) and a 3 nm gold nanoparticle (AuNP). The AuNP/azurin hybrid was assembled on a Au(111)-electrode surface in a two-step process. The AuNP was first attached to the Au(111) electrode via Au-S chemisorption of a 4,4'-biphenyidithiol (4,4'-BPDT) monolayer. This was followed by 1-decanethiol modification of the bound AuNP and hydrophobic binding of azurin to the AuNP. The Au(111)/AuNP/azurin system was characterized by atomic force microscopy (AFM), cyclic voltammetry (CV), and in situ electrochemical scanning tunneling microscopy (in situ STM). AFM and STM point to the feasibility of preparing both dense and sparsely populated AuNP monolayers. CV shows two pairs of voltammetric peaks at high scan rates, both around the azurin equilibrium potential. One pair of redox peaks follows closely that of azurin hydrophobically immobilized directly on a Au(111)/1-tetradecanethiol reference surface. The other pair, tentatively assigned to the AuNP/azurin hybrid, shows a 20-fold electron transfer rate enhancement over the reference system. This dual pattern is supported by in situ STM which shows two distinct contrasts. A strong contrast most likely arises either from azurin-free AuNPs or from AuNP-free azurin displaced onto the Au(111)/4,4'-BPDT surface. The other contrast, assigned to the AuNP/azurin hybrid, is weaker and fluctuates in time. Mechanisms of electronic conductivity of the AuNP/azurin system are discussed.

U2 - 10.1021/jp902611x

DO - 10.1021/jp902611x

M3 - Journal article

VL - 113

SP - 13993

EP - 14000

JO - The Journal of Physical Chemistry Part C

JF - The Journal of Physical Chemistry Part C

SN - 1932-7447

IS - 31

ER -