Ordered assembly and controlled electron transfer of the blue copper protein azurin at gold (111) single-crystal substrates

Qijin Chi, Jingdong Zhang, Jens E.T. Andersen, Jens Ulstrup

Research output: Contribution to journalArticle

209 Citations (Scopus)

Abstract

We have shown that Pseudomonas aeruginosa azurin can be immobilized on alkanethiol monolayers self-assembled on Au(111). Immobilization is achieved through hydrophobic interactions between the hydrophobic area around the copper atom in azurin and methyl heads of alkanethiol to form submonolayers or monolayers. In this orientation mode azurin molecules on Au(111) are oriented with the redox center (copper atom) facing the electrode surface. This is opposite to the orientation of azurin on bare gold which is via a surface disulfide group such as recently reported. Scanning tunneling microscopy (STM) with molecular resolution reveals that both well-ordered alkanethiol and protein adlayers are present. Adsorbed azurin molecules exhibit high stability and retain electron transfer (ET) function. Long-range interfacial ET between azurin and Au(111) across variable-length alkanethiol bridges was systematically investigated by different electrochemical techniques. Distance-dependent ET can be controlled by adjusting the length of the alkanethiol chain. The electrochemical ET rate constant is almost independent of the chain length up to ca. 9 methylene units but follows exponential distance decay with a decay factor (β) of 1.03 ± 0.02 per CH2 unit at longer chain lengths. Overvoltage-dependent ET was also examined. The results provide a strategy to ordered molecular assemblies, and controlled orientation and ET of azurin at atomically planar metallic surfaces. This approach can in principle be extended to other redox metalloproteins.

Original languageEnglish
Pages (from-to)4669-4679
Number of pages11
JournalJournal of Physical Chemistry B
Volume105
Issue number20
DOIs
Publication statusPublished - May 24 2001

Fingerprint

Azurin
Gold
Copper
electron transfer
assembly
Single crystals
gold
proteins
Proteins
copper
Electrons
single crystals
Substrates
Chain length
Atoms
overvoltage
Metalloproteins
Molecules
pseudomonas
disulfides

All Science Journal Classification (ASJC) codes

  • Physical and Theoretical Chemistry
  • Surfaces, Coatings and Films
  • Materials Chemistry

Cite this

@article{dd2bcdb4dcc0464a8f631dfadb041452,
title = "Ordered assembly and controlled electron transfer of the blue copper protein azurin at gold (111) single-crystal substrates",
abstract = "We have shown that Pseudomonas aeruginosa azurin can be immobilized on alkanethiol monolayers self-assembled on Au(111). Immobilization is achieved through hydrophobic interactions between the hydrophobic area around the copper atom in azurin and methyl heads of alkanethiol to form submonolayers or monolayers. In this orientation mode azurin molecules on Au(111) are oriented with the redox center (copper atom) facing the electrode surface. This is opposite to the orientation of azurin on bare gold which is via a surface disulfide group such as recently reported. Scanning tunneling microscopy (STM) with molecular resolution reveals that both well-ordered alkanethiol and protein adlayers are present. Adsorbed azurin molecules exhibit high stability and retain electron transfer (ET) function. Long-range interfacial ET between azurin and Au(111) across variable-length alkanethiol bridges was systematically investigated by different electrochemical techniques. Distance-dependent ET can be controlled by adjusting the length of the alkanethiol chain. The electrochemical ET rate constant is almost independent of the chain length up to ca. 9 methylene units but follows exponential distance decay with a decay factor (β) of 1.03 ± 0.02 per CH2 unit at longer chain lengths. Overvoltage-dependent ET was also examined. The results provide a strategy to ordered molecular assemblies, and controlled orientation and ET of azurin at atomically planar metallic surfaces. This approach can in principle be extended to other redox metalloproteins.",
author = "Qijin Chi and Jingdong Zhang and Andersen, {Jens E.T.} and Jens Ulstrup",
year = "2001",
month = "5",
day = "24",
doi = "10.1021/jp0105589",
language = "English",
volume = "105",
pages = "4669--4679",
journal = "Journal of Physical Chemistry B Materials",
issn = "1520-6106",
publisher = "American Chemical Society",
number = "20",

}

Ordered assembly and controlled electron transfer of the blue copper protein azurin at gold (111) single-crystal substrates. / Chi, Qijin; Zhang, Jingdong; Andersen, Jens E.T.; Ulstrup, Jens.

In: Journal of Physical Chemistry B, Vol. 105, No. 20, 24.05.2001, p. 4669-4679.

Research output: Contribution to journalArticle

TY - JOUR

T1 - Ordered assembly and controlled electron transfer of the blue copper protein azurin at gold (111) single-crystal substrates

AU - Chi, Qijin

AU - Zhang, Jingdong

AU - Andersen, Jens E.T.

AU - Ulstrup, Jens

PY - 2001/5/24

Y1 - 2001/5/24

N2 - We have shown that Pseudomonas aeruginosa azurin can be immobilized on alkanethiol monolayers self-assembled on Au(111). Immobilization is achieved through hydrophobic interactions between the hydrophobic area around the copper atom in azurin and methyl heads of alkanethiol to form submonolayers or monolayers. In this orientation mode azurin molecules on Au(111) are oriented with the redox center (copper atom) facing the electrode surface. This is opposite to the orientation of azurin on bare gold which is via a surface disulfide group such as recently reported. Scanning tunneling microscopy (STM) with molecular resolution reveals that both well-ordered alkanethiol and protein adlayers are present. Adsorbed azurin molecules exhibit high stability and retain electron transfer (ET) function. Long-range interfacial ET between azurin and Au(111) across variable-length alkanethiol bridges was systematically investigated by different electrochemical techniques. Distance-dependent ET can be controlled by adjusting the length of the alkanethiol chain. The electrochemical ET rate constant is almost independent of the chain length up to ca. 9 methylene units but follows exponential distance decay with a decay factor (β) of 1.03 ± 0.02 per CH2 unit at longer chain lengths. Overvoltage-dependent ET was also examined. The results provide a strategy to ordered molecular assemblies, and controlled orientation and ET of azurin at atomically planar metallic surfaces. This approach can in principle be extended to other redox metalloproteins.

AB - We have shown that Pseudomonas aeruginosa azurin can be immobilized on alkanethiol monolayers self-assembled on Au(111). Immobilization is achieved through hydrophobic interactions between the hydrophobic area around the copper atom in azurin and methyl heads of alkanethiol to form submonolayers or monolayers. In this orientation mode azurin molecules on Au(111) are oriented with the redox center (copper atom) facing the electrode surface. This is opposite to the orientation of azurin on bare gold which is via a surface disulfide group such as recently reported. Scanning tunneling microscopy (STM) with molecular resolution reveals that both well-ordered alkanethiol and protein adlayers are present. Adsorbed azurin molecules exhibit high stability and retain electron transfer (ET) function. Long-range interfacial ET between azurin and Au(111) across variable-length alkanethiol bridges was systematically investigated by different electrochemical techniques. Distance-dependent ET can be controlled by adjusting the length of the alkanethiol chain. The electrochemical ET rate constant is almost independent of the chain length up to ca. 9 methylene units but follows exponential distance decay with a decay factor (β) of 1.03 ± 0.02 per CH2 unit at longer chain lengths. Overvoltage-dependent ET was also examined. The results provide a strategy to ordered molecular assemblies, and controlled orientation and ET of azurin at atomically planar metallic surfaces. This approach can in principle be extended to other redox metalloproteins.

UR - http://www.scopus.com/inward/record.url?scp=0035942917&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0035942917&partnerID=8YFLogxK

U2 - 10.1021/jp0105589

DO - 10.1021/jp0105589

M3 - Article

AN - SCOPUS:0035942917

VL - 105

SP - 4669

EP - 4679

JO - Journal of Physical Chemistry B Materials

JF - Journal of Physical Chemistry B Materials

SN - 1520-6106

IS - 20

ER -