Hybrid Sol-Gel Surface-Enhanced Raman Sensor for Xylene Detection in Solution.

Verena Weber,Danilo Pedron,Roberto Pilot,Giovanni Mattei,Raffaella Signorini,Laura Brigo,Giovanna Brusatin

doi:10.3390/s21237912

Abstract

This paper reports on the fabrication and characterization of a plasmonic/sol-gel sensor for the detection of aromatic molecules. The sol-gel film was engineered using polysilsesquioxanes groups to capture the analyte, through π-π interaction, and to concentrate it close to the plasmonic surface, where Raman amplification occurs. Xylene was chosen as an analyte to test the sensor. It belongs to the general class of volatile organic compounds and can be found in water or in the atmosphere as pollutants released from a variety of processes; its detection with SERS is typically challenging, due to its low affinity toward metallic surfaces. The identification of xylene was verified in comparison with that of other aromatic molecules, such as benzene and toluene. Investigations were carried out on solutions of xylene in cyclohexane, using concentrations in the range from 0 to 800 mM, to evaluate the limit of detection (LOD) of about 40 mM.

Highlights

Surface enhanced Raman scattering (SERS) has been attracting much attention in the scientific community, especially in the field of chemical sensing, owing to its intrinsic high sensitivity and molecular specificity [1,2]
As an example, packed column gas chromatography has been combined with NMR techniques for the estimation of benzene and heavier aromatics in commercial gasoline [15]; solid-phase microextraction technique, followed by gas chromatography-mass spectrometry separation and detection, has been used for the determination of polycyclic aromatic hydrocarbons and benzene, toluene, ethylbenzene and xylene in snow water and water samples [16,17]
The two separate components, the Au NS substrate and the TEPS film, are easy to prepare and assemble, and their single properties work together to realize a complex system with enhanced SERS activity

Summary

Introduction

Surface enhanced Raman scattering (SERS) has been attracting much attention in the scientific community, especially in the field of chemical sensing, owing to its intrinsic high sensitivity and molecular specificity [1,2]. It has been successfully applied in different fields for the detection of materials such as explosives [3,4], toxic industrial chemicals [5], food contaminants and preservatives [6,7], biomolecules [8], bacteria [9], and dyes in works of art [10]. As an example, packed column gas chromatography has been combined with NMR techniques for the estimation of benzene and heavier aromatics in commercial gasoline [15]; solid-phase microextraction technique, followed by gas

Methods

Discussion

Conclusion