title: Romantic Story or Raman Scattering? Rose Petals as Ecofriendly, Low-Cost Substrates for Ultrasensitive Surface-Enhanced Raman Scattering.
abstract: In this Article, we present a facile approach for the preparation of ecofriendly substrates, based on common rose petals, for ultrasensitive surface-enhanced Raman scattering (SERS). The hydrophobic concentrating effect of the rose petals allows us to concentrate metal nanoparticle (NP) aggregates and analytes onto their surfaces. From a systematic investigation of the SERS performance when using upper and lower epidermises as substrates, we find that the lower epidermis, with its quasi-three-dimensional (quasi-3D) nanofold structure, is the superior biotemplate for SERS applications. The metal NPs and analytes are both closely packed in the quasi-3D structure of the lower epidermis, thereby enhancing the Raman signals dramatically within the depth of focus (DOF) of the Raman optical system. We have also found the effect of the pigment of the petals on the SERS performance. With the novel petal-based substrate, the SERS measurements reveal a detection limit for rhodamine 6G below the femtomolar regime (10(-15) M), with high reproducibility. Moreover, when we employ an upside-down drying process, the unique effect of the Wenzal state of the hydrophobic petal surface further concentrate the analytes and enhanced the SERS signals. Rose petals are green, natural materials that appear to have great potential for use in biosensors and biophotonics.
authors.affiliation: Department of Materials Science and Engineering, National Taiwan University, Number 1, Section 4, Roosevelt Road, Taipei, 10617 Taiwan (R.O.C.).
authors.forename: Sin-Yi
authors.initials: SY
authors.lastname: Chou
authors.affiliation: Department of Materials Science and Engineering, National Taiwan University, Number 1, Section 4, Roosevelt Road, Taipei, 10617 Taiwan (R.O.C.).
authors.forename: Chen-Chieh
authors.initials: CC
authors.lastname: Yu
authors.affiliation: Department of Materials Science and Engineering, National Taiwan University, Number 1, Section 4, Roosevelt Road, Taipei, 10617 Taiwan (R.O.C.).
authors.forename: Yu-Ting
authors.initials: YT
authors.lastname: Yen
authors.affiliation: Department of Materials Science and Engineering, National Taiwan University, Number 1, Section 4, Roosevelt Road, Taipei, 10617 Taiwan (R.O.C.).
authors.forename: Keng-Te
authors.initials: KT
authors.lastname: Lin
authors.affiliation: Department of Materials Science and Engineering, National Taiwan University, Number 1, Section 4, Roosevelt Road, Taipei, 10617 Taiwan (R.O.C.).
authors.forename: Hsuen-Li
authors.initials: HL
authors.lastname: Chen
authors.affiliation: Department of Materials Science and Engineering, National Taiwan University, Number 1, Section 4, Roosevelt Road, Taipei, 10617 Taiwan (R.O.C.).
authors.forename: Wei-Fang
authors.initials: WF
authors.lastname: Su
mesh_terms: D057230:Limit of Detection; D053768:Metal Nanoparticles / Q000032:analysis*; D010316:Particle Size; D012235:Rhodamines / Q000032:analysis*; D027826:Rosa / Q000737:chemistry*; D012834:Silver / Q000032:analysis*; D013059:Spectrum Analysis, Raman; D013499:Surface Properties
chemical_list: D012235:Rhodamines; C026188:rhodamine 6G; D012834:Silver