Depth profiling of APTES self-assembled monolayers using surface-enhanced confocal Raman microspectroscopy

Yingying Sun, Masahiro Yanagisawa, Masahiro Kunimoto, Masatoshi Nakamura, Takayuki Homma

    Research output: Contribution to journalArticle

    3 Citations (Scopus)

    Abstract

    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.

    Original languageEnglish
    Pages (from-to)1-6
    Number of pages6
    JournalSpectrochimica Acta - Part A: Molecular and Biomolecular Spectroscopy
    Volume184
    DOIs
    Publication statusPublished - 2017 Sep 5

    Fingerprint

    Depth profiling
    Self assembled monolayers
    high resolution
    frequency shift
    molecular structure
    Raman spectroscopy
    density functional theory
    nanoparticles
    Molecular structure
    Density functional theory
    scanning
    glass
    Nanoparticles
    Scanning
    molecules
    Glass
    Molecules
    Substrates
    gamma-aminopropyltriethoxysilane

    Keywords

    • APTES self-assembled monolayers
    • Depth profile
    • Nano resolution
    • Surface-enhanced confocal Raman microspectroscopy

    ASJC Scopus subject areas

    • Analytical Chemistry
    • Atomic and Molecular Physics, and Optics
    • Instrumentation
    • Spectroscopy

    Cite this

    Depth profiling of APTES self-assembled monolayers using surface-enhanced confocal Raman microspectroscopy. / Sun, Yingying; Yanagisawa, Masahiro; Kunimoto, Masahiro; Nakamura, Masatoshi; Homma, Takayuki.

    In: Spectrochimica Acta - Part A: Molecular and Biomolecular Spectroscopy, Vol. 184, 05.09.2017, p. 1-6.

    Research output: Contribution to journalArticle

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    AU - Homma, Takayuki

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