(78e) Carbon Nanofiber Mats for Surface Enhanced Raman Spectroscopy

Carbon Nanofiber Mats for Surface Enhanced Raman Spectroscopy

by

Juan F. Yee-De-León¹, Victor H. Perez-Gonzalez¹, Roberto C. Gallo-Villanueva¹, Sergio O. Martinez-Chapa^1,*

¹ Sensors and Devices Research Group, School of Engineering and Sciences, Tecnológico de Monterrey, México

*Correspondence should be addressed to smart@itesm.mx

Abstract

Surface Enhanced Raman Spectroscopy (SERS) is a powerful readout technique that yields qualitative and quantitative information of chemical species and biomolecules at low concentrations. The effectiveness of the technique is closely related to the SERS-active substrate employed. Currently, nano-fabrication techniques have enabled the development of highly active and reproducible SERS-substrates, however, very specialized personnel and equipment are needed to construct these substrates, increasing the related cost of sample analysis using SERS as the readout technique. This situation has hampered the use of SERS in real life situations, which has motivated to the quest of novel nanomaterials and methodologies for producing homogenous, highly sensitive, scalable and low cost SERS-active substrates for chemical trace detection and biological applications.

In this work, polyacrylonitrile (PAN) nanofiber mats were fabricated via far-field electrospinning. These mats were subjected to a carbonization step to obtain nanofiber mats composed of carbon. The carbon nanofiber mats obtained were oxidized using a solution composed of 3:1 (H₂SO₄:HNO₃) v/v, and later, the surface of the nanofibers was functionalized with aminosilanes, in order to attach gold nanoparticles to the carbon nanofiber mats. Here, we present a first approximation to the use of carbon nanofiber mats as structural three-dimensional scaffolds for supporting metallic nanoparticles for its use as SERS-active substrates. The structure’s high surface area and porosity, derivatives from the three-dimensional entanglement of the nanofibers, allows easy access and interaction of more analyte molecules with the metallic nanostructures located onto the nanofiber’s surface. A higher number of metallic nanoparticles adsorbed increases the sensitivity and saturation levels of these substrates with regard to 2D SERS-active substrates.