title: Vertically aligned gold nanorod monolayer on arbitrary substrates: self-assembly and femtomolar detection of food contaminants.
abstract: Public attention to the food scandals raises an urgent need to develop effective and reliable methods to detect food contaminants. The current prevailing detections are primarily based upon liquid chromatography, mass spectroscopy, or colorimetric methods, which usually require sophisticated and time-consuming steps or sample preparation. Herein, we develop a facile strategy to assemble the vertically aligned monolayer of Au nanorods with a nominal 0.8 nm gap distance and demonstrate their applications in the rapid detection of plasticizers and melamine contamination at femtomolar level by surface-enhanced Raman scattering spectroscopy (SERS). The SERS signals of plasticizers are sensitive down to 0.9 fM concentrations in orange juices. It is the lowest detection limit reported to date, which is 7 orders of magnitude lower than the standard of United States (6 ppb). The highly organized vertical arrays generate the reproducible "SERS-active sites" and can be achieved on arbitrary substrates, ranging from silicon, gallium nitride, glass to flexible poly(ethylene naphthalate) substrates.
authors.affiliation: Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore 637371.
authors.forename: Bo
authors.initials: B
authors.lastname: Peng
authors.forename: Guangyuan
authors.initials: G
authors.lastname: Li
authors.forename: Dehui
authors.initials: D
authors.lastname: Li
authors.forename: Stephanie
authors.initials: S
authors.lastname: Dodson
authors.forename: Qing
authors.initials: Q
authors.lastname: Zhang
authors.forename: Jun
authors.initials: J
authors.lastname: Zhang
authors.forename: Yih Hong
authors.initials: YH
authors.lastname: Lee
authors.forename: Hilmi Volkan
authors.initials: HV
authors.lastname: Demir
authors.forename: Xing Yi
authors.initials: XY
authors.lastname: Ling
authors.forename: Qihua
authors.initials: Q
authors.lastname: Xiong
mesh_terms: D001628:Beverages / Q000032:analysis*; D032084:Citrus sinensis / Q000737:chemistry*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D005504:Food Analysis / Q000295:instrumentation*; D005506:Food Contamination / Q000032:analysis*; D006046:Gold / Q000737:chemistry*; D053768:Metal Nanoparticles / Q000737:chemistry / Q000648:ultrastructure; D008968:Molecular Conformation; D043942:Nanotubes / Q000737:chemistry* / Q000648:ultrastructure; D010968:Plasticizers / Q000032:analysis; D013059:Spectrum Analysis, Raman / Q000295:instrumentation*; D014227:Triazines / Q000032:analysis
chemical_list: D010968:Plasticizers; D014227:Triazines; D006046:Gold; C011907:melamine