Vibrational Changes Induced by Electron Transfer in Surface Bound Azurin Metalloprotein Studied by Tip-Enhanced Raman Spectroscopy and Scanning Tunneling Microscopy
Author(s)
Kradolfer, Stefan
Lipiec, Ewelina
Date Issued
2017
Type
article
Volume
11
Start Page
12824
End Page
12831
Journal
Abstract
The copper protein azurin, due to the peculiar coupling of its optical and vibronic properties with electron transfer (ET) and its biorecognition capabilities, is a very promising candidate for bioelectronic, bio-optoelectronic and biosensor applications. However, a complete understanding of the fundamental processes relating azurin ET and its optical and vibronic characteristics with the charge transport mechanisms occurring in proteins bound to a conductive surface, the typical scenario for a biosensor or bioelectronic component, is still lacking. We studied azurin proteins bound to a gold electrode surface by scanning tunneling microscopy combined with tip-enhanced Raman spectroscopy (STM-TERS). Robust TER spectra were obtained, and the protein's vibronic response under optical excitation in resonance with its ligand-to-metal charge transfer band was found to be affected by the tunneling parameters, indicating a direct involvement of the active site vibrations in the electron transport process. © 2017 American Chemical Society.
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ACSnano_accepted_VQR.pdf
Description
accepted version
Size
1.47 MB
Format
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Checksum (MD5)
de29c2bfd4492e28b2e4c9c188dfdd09
Project(s)
PRIN 2012NRRP5J
IG15866