title: Chemical and Biological Sensing Using Diatom Photonic Crystal Biosilica With In-Situ Growth Plasmonic Nanoparticles.
abstract: In this paper, we described a new type of bioenabled nano-plasmonic sensors based on diatom photonic crystal biosilica with in-situ growth silver nanoparticles and demonstrated label-free chemical and biological sensing based on surface-enhanced Raman scattering (SERs) from complex samples. Diatoms are photosynthetic marine micro-organisms that create their own skeletal shells of hydrated amorphous silica, called frustules, which possess photonic crystal-like hierarchical micro- & nanoscale periodic pores. Our research shows that such hybrid plasmonic-biosilica nanostructures formed by cost-effective and eco-friendly bottom-up processes can achieve ultra-high limit of detection for medical applications, food sensing, water/air quality monitoring and geological/space research. The enhanced sensitivity comes from the optical coupling of the guided-mode resonance of the diatom frustules and the localized surface plasmons of the silver nanoparticles. Additionally, the nanoporous, ultra-hydrophilic diatom biosilica with large surface-to-volume ratio can concentrate more analyte molecules to the surface of the SERS substrates, which can help to detect biomolecules that cannot be easily adsorbed by metallic nanoparticles.
authors.forename: Xianming
authors.initials: X
authors.lastname: Kong
authors.forename: Kenny
authors.initials: K
authors.lastname: Squire
authors.forename: Erwen
authors.initials: E
authors.lastname: Li
authors.forename: Paul
authors.initials: P
authors.lastname: LeDuff
authors.forename: Gregory L
authors.initials: GL
authors.lastname: Rorrer
authors.forename: Suning
authors.initials: S
authors.lastname: Tang
authors.forename: Bin
authors.initials: B
authors.lastname: Chen
authors.forename: Christopher P
authors.initials: CP
authors.lastname: McKay
authors.forename: Rafael
authors.initials: R
authors.lastname: Navarro-Gonzalez
authors.forename: Alan X
authors.initials: AX
authors.lastname: Wang
mesh_terms: D015374:Biosensing Techniques / Q000379:methods*; D017377:Diatoms / Q000737:chemistry*; D017785:Photons; D012822:Silicon Dioxide / Q000737:chemistry*; D013059:Spectrum Analysis, Raman / Q000379:methods*
chemical_list: D012822:Silicon Dioxide