title: Humic acids-based one-step fabrication of SERS substrates for detection of polycyclic aromatic hydrocarbons.
abstract: A facile one-step approach to fabricate substrates for surface-enhanced Raman scattering (SERS) detection of polycyclic aromatic hydrocarbons (PAHs) was explored by reduction of silver nitrate with humic acids (HAs). This simple process readily delivers silver nanoparticles (Ag NPs) decorated with HAs (HAs-Ag NPs), and an average diameter of 50 nm. More importantly, it compares favorably to Ag NPs prepared by the usual sodium citrate method, HAs-Ag NPs show excellent SERS activity for PAHs and display a remarkable capacity to absorb aromatic molecules through presumed π-π stacking interactions. Furthermore, the HAs-Ag NPs displayed good SERS stability, possibly due to the fact that HAs form loose coils or networks around the nanoparticles thus preventing aggregation. The investigation of qualitative and quantitative detection of PAHs on HAs-Ag NPs indicate that different PAHs can be distinguished easily from their discriminant SERS peaks, and the SERS responses exhibited a linear dependence on PAH concentrations over two orders of magnitude, with tens of nM detection limits. In addition, the HAs-Ag NPs performed well in the multicomponent analysis of PAH mixtures by the SERS technique without pre-separation.
authors: State Key Laboratory of Bioreactor Engineering & Department of Chemistry, East China University of Science and Technology, Shanghai 200237, China.
authors: Lu-Lu
authors: LL
authors: Qu
authors: Yuan-Ting
authors: YT
authors: Li
authors: Da-Wei
authors: DW
authors: Li
authors: Jin-Qun
authors: JQ
authors: Xue
authors: John S
authors: JS
authors: Fossey
authors: Yi-Tao
authors: YT
authors: Long
mesh_terms: D006812:Humic Substances / Q000032:analysis*; D057230:Limit of Detection; D053758:Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D010084:Oxidation-Reduction; D010316:Particle Size; D011084:Polycyclic Aromatic Hydrocarbons / Q000032:analysis*; D012722:Sewage / Q000032:analysis; D012834:Silver / Q000737:chemistry*; D012835:Silver Nitrate / Q000737:chemistry; D013059:Spectrum Analysis, Raman / Q000379:methods*; D014874:Water Pollutants, Chemical / Q000032:analysis*
chemical_list: D006812:Humic Substances; D011084:Polycyclic Aromatic Hydrocarbons; D012722:Sewage; D014874:Water Pollutants, Chemical; D012834:Silver; D012835:Silver Nitrate