Coupling Single-Drop Microextraction with SERS: A Demonstration Using p-MBA on Gold Nanohole Array Substrate

Abstract

Single-drop microextraction (SDME) was coupled with surface-enhanced Raman scattering (SERS) to provide sample extraction and pre-concentration for detection of analyte at low concentrations. A gold nanohole array substrate (AuNHAS), fabricated by interference lithography, was used as SERS substrate and para-mercaptobenzoic acid (p-MBA) was tested as a probe molecule, in the concentration range 10−8–10−4 mol L−1. With this approach, a limit of 10−7 mol L−1 was clearly detected. To improve the detection to lower p-MBA concentration, as 10−8 mol L−1, the SDME technique was applied. The p-MBA Raman signature was detected in two performed extractions and its new concentration was determined to be ~4.6 × 10−5 mol L−1. This work showed that coupling SDME with SERS allowed a rapid (5 min) and efficient pre-concentration (from 10−8 mol L−1 to 10−5 mol L−1), detection, and quantification of the analyte of interest, proving to be an interesting analytical tool for SERS applications.

Applications of surface‐enhanced Raman spectroscopy in environmental detection

“…One strategy of minimizing matrix interference is using more advanced sample purification methods. Previously, single drop microextraction (SDME) has been used to pre‐concentrate analytes in simple sample matrices before SERS detection, allowing for more concentrated samples and, thus, significantly lower limits of detection 249,250 . However, the amount of research combining SDME with SERS is very limited, and to our knowledge there have been no studies which investigated SDME's abilities to improve SERS detection in complex environmental matrices, which is a promising area for future research.…”

“…Previously, single drop microextraction (SDME) has been used to pre‐concentrate analytes in simple sample matrices before SERS detection, allowing for more concentrated samples and, thus, significantly lower limits of detection. 249 , 250 However, the amount of research combining SDME with SERS is very limited, and to our knowledge there have been no studies which investigated SDME's abilities to improve SERS detection in complex environmental matrices, which is a promising area for future research. Another strategy to reduce matrix interference is integrating materials with purification and enrichment properties into SERS nanosubstrates.…”

Frontiers of light manipulation in natural, metallic, and dielectric nanostructures

“…Then, the obtained EF and LOD for the detection of the chosen compound have been reported. For example, nanodisks or nanoholes arrays can be fabricated with high throughput and high reliability showing good results both in terms of EF and LOD [226][227][228]. The performance comparison in the detection of small molecules of thiophenol using hybrid gold/silicon nanodisks array [152] and gold nanohole array [228] is reported in Panels a and b of Fig.…”

“…b (blue box) A SEM image (on the left) and the SERS signals (on the right) of a gold nanohole array in detecting para-mercaptobenzoic acid molecules. Reprinted with permission from[228]. c (yellow box) A SEM image (on the left) and the SERS signals (on the right) of an aperiodic nanogalaxy gold array for detection of p-Mercaptoaniline.…”