| Autor: |
Sánchez-Alvarado AB; Department of Chemistry, Rice University, Houston, Texas 77005, United States.; Laboratory for Nanophotonics, Rice University, Houston, Texas 77005, United States., Zhou J; Department of Materials Science and Nanoengineering, Rice University, Houston, Texas 77005, United States.; Laboratory for Nanophotonics, Rice University, Houston, Texas 77005, United States., Jin P; Department of Chemical and Biomolecular Engineering, Rice University, Houston, Texas 77005, United States., Neumann O; Department of Electrical and Computer Engineering, Rice University, Houston, Texas 77005, United States.; Laboratory for Nanophotonics, Rice University, Houston, Texas 77005, United States., Senftle TP; Department of Chemical and Biomolecular Engineering, Rice University, Houston, Texas 77005, United States., Nordlander P; Department of Materials Science and Nanoengineering, Rice University, Houston, Texas 77005, United States.; Department of Physics and Astronomy, Rice University, Houston, Texas 77005, United States.; Department of Electrical and Computer Engineering, Rice University, Houston, Texas 77005, United States.; Laboratory for Nanophotonics, Rice University, Houston, Texas 77005, United States., Halas NJ; Department of Chemistry, Rice University, Houston, Texas 77005, United States.; Department of Physics and Astronomy, Rice University, Houston, Texas 77005, United States.; Department of Electrical and Computer Engineering, Rice University, Houston, Texas 77005, United States.; Laboratory for Nanophotonics, Rice University, Houston, Texas 77005, United States. |
| Abstrakt: |
Polycyclic aromatic hydrocarbons (PAHs) constitute a class of universally prevalent carcinogenic environmental contaminants. It is increasingly recognized, however, that PAHs derivatized with oxygen, sulfur, or nitrogen functional groups are frequently more dangerous than their unfunctionalized counterparts. This much larger family of chemicals─polycyclic aromatic compounds─PACs─is far less well characterized than PAHs. Using surface-enhanced Raman and IR Absorption spectroscopies (SERS + SEIRA) combined on a single substrate, along with density functional theoretical (DFT) calculations, we show that direct chemical detection and identification of PACs at sub-parts-per-billion concentration can be achieved. Focusing our studies on 9,10-anthraquinone, 5,12-tetracenequinone, 9-nitroanthracene, and 1-nitropyrene as model PAC contaminants, detection is made possible by incorporating a hydroxy-functionalized self-assembled monolayer that facilitates hydrogen bonding between analytes and the SERS + SEIRA substrate. 5,12-Tetracenequinone was detected at 0.3 ppb, and the limit of detection was determined to be 0.1 ppb using SEIRA alone. This approach is straightforwardly extendable to other families of analytes and will ultimately facilitate fieldable chemical detection of these dangerous yet largely overlooked environmental contaminants. |
