TY - JOUR
T1 - Depth profiling of APTES self-assembled monolayers using surface-enhanced confocal Raman microspectroscopy
AU - Sun, Yingying
AU - Yanagisawa, Masahiro
AU - Kunimoto, Masahiro
AU - Nakamura, Masatoshi
AU - Homma, Takayuki
N1 - Funding Information:
This research was partially supported by “Development of Systems and Technology for Advanced Measurement and Analysis”, and “Grant-in-Aid for Scientific Research of the MEXT Japan (Grant number is 26600065)”. The manuscript has been edited by “Editage”.
Publisher Copyright:
© 2017 Elsevier B.V.
PY - 2017/9/5
Y1 - 2017/9/5
N2 - The internal structure of self-assembled monolayers (SAMs) such as 3-aminopropyltriethoxysilane (APTES) fabricated on a glass substrate is difficult to characterize and analyze at nanometer level. In this study, we employed surface-enhanced Raman spectroscopy (SERS) to study the internal molecular structure of APTES SAMs. The sample APTES SAMs were deposited with Ag nanoparticles to enhance the Raman signal and to obtain subtler structure information, which were supported by density functional theory calculations. In addition, in order to carry out high-resolution analysis, especially for vertical direction, a fine piezo electric positioner was used to control the depth scanning with a step of 0.1 nm. We measured and distinguished the vertical Raman intensity variations of specific groups in APTES, such as Ag/NH2, CH2, and Si[sbnd]O, with high resolution. The interfacial bond at the two interfaces of Ag-APTES and APTES-SiO2 was identified. Moreover, APTES molecule orientation was demonstrated to be inhomogeneous from frequency shift.
AB - The internal structure of self-assembled monolayers (SAMs) such as 3-aminopropyltriethoxysilane (APTES) fabricated on a glass substrate is difficult to characterize and analyze at nanometer level. In this study, we employed surface-enhanced Raman spectroscopy (SERS) to study the internal molecular structure of APTES SAMs. The sample APTES SAMs were deposited with Ag nanoparticles to enhance the Raman signal and to obtain subtler structure information, which were supported by density functional theory calculations. In addition, in order to carry out high-resolution analysis, especially for vertical direction, a fine piezo electric positioner was used to control the depth scanning with a step of 0.1 nm. We measured and distinguished the vertical Raman intensity variations of specific groups in APTES, such as Ag/NH2, CH2, and Si[sbnd]O, with high resolution. The interfacial bond at the two interfaces of Ag-APTES and APTES-SiO2 was identified. Moreover, APTES molecule orientation was demonstrated to be inhomogeneous from frequency shift.
KW - APTES self-assembled monolayers
KW - Depth profile
KW - Nano resolution
KW - Surface-enhanced confocal Raman microspectroscopy
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U2 - 10.1016/j.saa.2017.04.036
DO - 10.1016/j.saa.2017.04.036
M3 - Article
C2 - 28475958
AN - SCOPUS:85018368287
SN - 1386-1425
VL - 184
SP - 1
EP - 6
JO - Spectrochimica Acta - Part A: Molecular and Biomolecular Spectroscopy
JF - Spectrochimica Acta - Part A: Molecular and Biomolecular Spectroscopy
ER -