Immobilization of green-synthesized silver nanoparticles for micro- and nano-spectroscopic applications: What is the role of used short amino- and thio-linkers and immobilization procedure on the SERS spectra?

Marie Švecová; Oleksandr Volochanskyi; Marcela Dendisová; David Palounek; Pavel Matějka

doi:10.1016/j.saa.2020.119142

Immobilization of green-synthesized silver nanoparticles for micro- and nano-spectroscopic applications: What is the role of used short amino- and thio-linkers and immobilization procedure on the SERS spectra?

Spectrochim Acta A Mol Biomol Spectrosc. 2021 Feb 15:247:119142. doi: 10.1016/j.saa.2020.119142. Epub 2020 Nov 4.

Authors

Marie Švecová¹, Oleksandr Volochanskyi², Marcela Dendisová³, David Palounek³, Pavel Matějka³

Affiliations

¹ Department of Analytical Chemistry, Faculty of Chemical Engineering, University of Chemistry and Technology Prague, Technická 5, Praha 6 166 28, Czech Republic. Electronic address: svecovam@vscht.cz.
² Department of Low-Dimensional Systems, J. Heyrovský Institute of Physical Chemistry, Czech Academy of Sciences, v.v.i., Dolejškova 3, Prague 8 18223, Czech Republic; Department of Physical Chemistry, Faculty of Chemical Engineering, University of Chemistry and Technology Prague, Technická 5, Praha 6 166 28, Czech Republic.
³ Department of Physical Chemistry, Faculty of Chemical Engineering, University of Chemistry and Technology Prague, Technická 5, Praha 6 166 28, Czech Republic.

PMID: 33189978
DOI: 10.1016/j.saa.2020.119142

Abstract

Immobilization of nanoparticles (NPs) is a technique suitable for the preparation of large-scale substrates for surface-enhanced vibrational spectroscopy including micro- and nano-spectroscopic applications. The developed immobilization method provides the enhancing properties of the roughened substrate surface to be maintained for techniques like surface-enhanced Raman scattering (SERS) spectroscopy, however, at the same time the morphology is not limiting for related near-field (scanning probe) techniques. The study is focused on the comparison of different immobilization procedures of Ag nanoparticles and finding the relationship between preparation procedures leading to convenient surface morphology and the quality of the observed signal of the model analyte (riboflavin) using SERS. Amino-linker (3-aminopropyl)trimethoxysilane (APTMS) and four thio-linkers (cysteine, 3-mercaptopropanoic acid, 2-mercaptoethanol, and 2,2'-oxydiethanthiol) using five immobilization procedures at three different temperatures (23 °C, 40 °C, and 70 °C) were compared. Surface morphology was monitored by scanning electron microscopy and atomic force microscopy. The SERS spectra of riboflavin were evaluated in terms of the intensity and the resolution of individual bands. The spectral dataset was inspected by multivariate statistical methods - principal component analysis and discriminant analysis. The evaluation of spectra and statistical models show the influence of the used linker and AgNPs immobilization procedure on the spectral output. APTMS linker is less suitable; much more appropriate are thio-linkers deposited on an evaporated Au layer on a glass slide. The best spectral parameters were obtained for 2,2'-oxydiethanthiol and 23 °C.

Keywords: Atomic force microscopy; Immobilization procedures; Linkers; Riboflavin; SERS spectroscopy; Silver nanoparticles.