Enhancing surface plasmon resonances of metallic nanoparticles by diatom biosilica

Abstract

Diatoms are single-celled algaes that make photonic-crystal-like silica shells or frustules with hierarchical micro- & nano-scale features consisting of two-dimensional periodic pores. This article reports the use of diatom frustules as an integration platform to enhance localized surface plasmon resonances of self-assembled silver nanoparticles (NPs) on the surface of diatom frustules. Theoretical and experimental results show enhanced localized surface plasmons due to the coupling with the guided-mode resonances of the frustules. We observed 2 × stronger optical extinction and over 4 × higher sensitivity of surface-enhanced Raman scattering of Rhodmine 6G from the NPs-on-diatom than the NPs-on-glass structure.

Surface-Enhanced Raman Spectroscopy Sensors From Nanobiosilica With Self-Assembled Plasmonic Nanoparticles

“…Potential applications of diatoms for the detection of antibodies, solar cells, electroluminescent display, high surface area battery materials, photoluminescence, and nanoplasmonic photonic devices have been explored by many researchers [13]–[19]. Our previous work theoretically and experimentally demonstrated that the photonic-crystal-like structure of a diatom frustule can provide GMRs in the visible wavelength range [20]. NPs-on-diatom nanostructures provide enhanced plasmonic resonances at visible wavelengths due to the intrinsic surface plasmonic resonances of silver (Ag) NPs coupled with the GMRs of diatom frustules [20].…”

Biogenic nanomaterials from photosynthetic microorganisms

“…Diatom frustules have shown great potential as biosensor platforms because of their ability to accept functional groups and because of their variable photoluminescence (PL), Raman spectroscopic and optoelectric properties in the presence of target molecules and surface modifications [62][63][64][65]. The structural and material characteristics of diatom frustules even have potential as optical microsystems, such as a micro-monochromators [66].…”

“…A plasmonic sensor was also developed when silver NP were loaded into the frustule pores of the diatom Pinnularia sp. [63 ]. First, cells were deposited on a glass substrate, fixed with ethanol, UV-O 3 cleaned, annealed, functionalized with APTES and exposed to an Ag colloidal suspension, which results in self-ordered Ag NP.…”

“…This imparts a resonance between the localized surface plasmons and the guided-mode plasmons. This allowed the SERS detection of the model compound Rhodamine 6G with four times more intensity than Ag NP loaded onto glass, indicating both the importance of the diatom biosilica and the potential of biosilica-Ag NP composites as biosensor materials [63 ]. A study by the Brunner group [70] used two different processes to form NP arrays of Ag, Au, and Pt on the biosilica of Eucampia zodiacus and Coscinodiscus wailesii.…”

Label-free optical sensing on hybrid plasmonic-nanobiosilica platforms

“…The increase of the redshift magnitude of the LSPs for a dimer is attributed to the enhancement of the particle nearfield coupling. The preparation of diatom frustules can be found in our previous work [10]. For the Ag nanoparticles synthesis, the colloidal was prepared by the Lee and Mesel Method [11].…”