title: Silver nanoparticle aggregates on metal fibers for solid phase microextraction-surface enhanced Raman spectroscopy detection of polycyclic aromatic hydrocarbons.
abstract: Solid phase microextraction (SPME), a solvent free technique for sample preparation, has been successfully coupled with GC, GC-MS, and HPLC for environmental analysis. In this work, a method combining solid phase microextraction with surface enhanced Raman spectroscopy (SERS) is developed for detection of polycyclic aromatic hydrocarbons (PAHs). Silver nanoparticle aggregates were deposited on the Ag-Cu fibers via layer-by-layer deposition, which were modified with propanethiol (PTH). The SERS-active SPME fiber was immersed in water directly to extract PAHs and then detected using a portable Raman spectrometer. The pronounced valence vibration of the C-C bond at 1030 cm(-1) was chosen as an internal standard peak for the constant concentration of PTH. The RSD values of the stability and the uniformity of the SERS-active SPME fiber are 2.97% and 5.66%, respectively. A log-log plot of the normalized SERS intensity versus fluoranthene concentration showed a linear relationship (R(2) = 0.95). The detection limit was 7.56 × 10(-10) M and the recovery rate of water samples was in the range of 95% to 115%. The method can also be applied to detection of PAH mixtures, and each component of the mixtures can be distinguished by Raman characteristic peaks. The SERS-active SPME fiber could be further confirmed by GC-MS.
authors.affiliation: National Engineering Research Center for Colloidal Materials and Key Laboratory for Colloid & Interface Chemistry of Education Ministry, Department of Chemistry, Shandong University, Jinan Shandong, 250100, P. R. China. jhzhan@sdu.edu.cn.
authors.forename: Cuicui
authors.initials: C
authors.lastname: Liu
authors.forename: Xiaoli
authors.initials: X
authors.lastname: Zhang
authors.forename: Limei
authors.initials: L
authors.lastname: Li
authors.forename: Jingcheng
authors.initials: J
authors.lastname: Cui
authors.forename: Yu-e
authors.initials: YE
authors.lastname: Shi
authors.forename: Le
authors.initials: L
authors.lastname: Wang
authors.forename: Jinhua
authors.initials: J
authors.lastname: Zhan
mesh_terms: D003300:Copper / Q000737:chemistry*; D053768:Metal Nanoparticles / Q000737:chemistry*; D011084:Polycyclic Aromatic Hydrocarbons / Q000032:analysis* / Q000302:isolation & purification*; D012834:Silver / Q000737:chemistry*; D052617:Solid Phase Microextraction / Q000379:methods*; D013059:Spectrum Analysis, Raman / Q000379:methods*
chemical_list: D011084:Polycyclic Aromatic Hydrocarbons; D012834:Silver; D003300:Copper