Gold nanorods as SERS substrate for the ultratrace detection of cocaine in non-pretreated oral fluid samples
This work shows the capability of surface-enhanced Raman spectroscopy (SERS) to detect ultratraces of cocaine(COC) in oral fluid (OF). It proposes a new solid substrate made of gold nanorods (Au NRs) to perform sensitiveanalyses of this complex matrix without any sample pretreatment. The Au NRs were...
| Autores: | , , , , |
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| Formato: | artículo |
| Fecha de publicación: | 2018 |
| País: | España |
| Recursos: | Universidad de Alcalá (UAH) |
| Repositorio: | e_Buah Biblioteca Digital Universidad de Alcalá |
| Idioma: | inglés |
| OAI Identifier: | oai:ebuah.uah.es:10017/46567 |
| Acesso em linha: | http://hdl.handle.net/10017/46567 https://dx.doi.org/10.1016/j.colsurfa.2018.05.068 |
| Access Level: | acceso abierto |
| Palavra-chave: | Cocaine nanoparticles gold nanorods oral fluid surface enhanced Raman spectroscopy orthogonal partial least squares to latent structures-discriminate analysis (OPLS-DA) Química Chemistry |
| Resumo: | This work shows the capability of surface-enhanced Raman spectroscopy (SERS) to detect ultratraces of cocaine(COC) in oral fluid (OF). It proposes a new solid substrate made of gold nanorods (Au NRs) to perform sensitiveanalyses of this complex matrix without any sample pretreatment. The Au NRs were synthetized optimizing thesynthesis conditions, and then characterized and tested as SERS substrate. The presented results demonstratedthat the SERS methodology was able to detect COC in OF with a limit of detection (LOD) as low as 10 ng/mL.This value was five orders of magnitude smaller than the one obtained with Raman spectroscopy (RS) and in theorder of the cut-off value (8 ng/mL) established for confirmatory test of COC in OF. Besides, a multivariateanalysis (OPLS-DA) applied on the samples analysed by SERS evidenced that it was possible to discriminateamong various COC concentrations. These are quite positive results because even the 1 ng/mL COC concentration sample could be identified as different from the OF sample. In addition, the absence of samplepretreatment and the ease of the proposed method, allowed performing rapid and non-destructive analyses,making the method suitable for in situ forensic analyses. |
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