Thiolated Graphene Oxide Nanoribbons as Templates for Anchoring Gold Nanoparticles: Two-Dimensional Nanostructures for SERS.

Jose M González‐Domínguez,Moreno Meneghetti,Adrian Ostric,Lucio Litti,Andrea Colusso,Tatiana Da Ros

doi:10.1002/cplu.201900150

Abstract

Graphene oxide nanoribbons (GONRs), obtained from the oxidative unzipping of carbon nanotubes, have been investigated as building blocks towards reaching active platforms in surface-enhanced Raman scattering (SERS). The complete development of carbon nanomaterials is strongly related to the exploitation of their chemical versatility, so this work is focused on the positive effect that a specific chemical functionalization provides to the SERS effect when gold nanoparticles are used. The covalent derivatization of GONRs with terminal thiol groups boosts their interaction with different types of gold nanoparticles (namely, 'naked' or citrate-stabilized), and the resulting two-dimensional aggregates show an intense enhancement of the Raman scattering from the carbon nanostructures because of their two-dimensional extended aggregation pattern. The SERS effect has been corroborated by theoretical calculations and a conceptual proof of SERS-based sensing.

Highlights

Since the observation of the surface-enhanced Raman scattering (SERS) phenomenon in the mid-late ’70s, nowadays matching and overpassing high-sensitivity landmark techniques such as absorbance or fluorescence spectroscopies. [1] SERS belongs to the family of molecular spectroscopies, and it is based on the plasmon-assisted scattering of molecules, which are near certain metal surfaces, supporting local surface plasmon resonance
While the latter is consistent with the multi-walled carbon nanotubes (MWCNTs) diameters specified by the manufacturer, the lengths observed in Graphene oxide nanoribbons (GONRs) suggest that MWCNTs underwent a certain degree of transversal cutting together with the unzipping mechanism
The AFM analysis of GONRs and GONRs-SH (Fig. 2g and h respectively) shows individual nanostructures with a height profile across the nanoribbons of 3-7 nm, which corresponds to the height of 2-3 graphene sheets, in agreement with typical results reported in literature.[14]

Summary

Introduction

Since the observation of the surface-enhanced Raman scattering (SERS) phenomenon in the mid-late ’70s, nowadays matching and overpassing high-sensitivity landmark techniques such as absorbance or fluorescence spectroscopies. [1] SERS belongs to the family of molecular spectroscopies, and it is based on the plasmon-assisted scattering of molecules, which are near certain metal surfaces, supporting local surface plasmon resonance.

Results

Conclusion