Synthesis of High-Performance Photonic Crystal Film for SERS Applications via Drop-Coating Method

Abstract

Silica nanospheres with a well-controlled particle size were prepared via a nucleation-to-growth synthesis process. A facile method is proposed for improving the self-assembly behavior of silica colloidal particles in droplet coatings by the simple controlling of the drying temperature. It is shown that a periodically arranged, opal-structured, photonic crystal film with a large area of approximately 4.0 cm2 can be prepared, even when the particle size is up to 840 nm. When the band gap of the silica photonic crystals falls in the visible-light region, the crystals exhibit distinct structural colors. Moreover, the wavelength of the reflected light increases with an increasing particle size of silica. When the photonic band gap overlaps the wavelength of the laser source, the overall Raman spectrum intensity is significantly enhanced. Accordingly, the proposed nucleation-to-growth process and drop-coating method provides a cheap and simple approach for the manufacture of uniform sized silica and surface-enhanced Raman scattering substrates, respectively.

Antimicrobial Activities of Pistacia lentiscus Essential Oils Nanoencapsulated into Hydroxypropyl-beta-cyclodextrins

“… 69 Also, agglomerations between the suspension particles can be indicated with PDI values greater than 0.07, whereas lower PDI values (<0.07) refer to very few agglomerations. 70 Free HPβCD showed an average particle size of 1.125 μm (1125.73 nm) and a highly heterogeneous and dispersed system with a PDI value of 0.801. Conversely, the PO-ICs suspension displayed greater stability with smaller particles and a less dispersed system.…”

“…A PDI value greater than 0.7 indicates a highly polydisperse system, whereas a value of less than 0.08 refers to a nearly monodispersed system . Also, agglomerations between the suspension particles can be indicated with PDI values greater than 0.07, whereas lower PDI values (<0.07) refer to very few agglomerations . Free HPβCD showed an average particle size of 1.125 μm (1125.73 nm) and a highly heterogeneous and dispersed system with a PDI value of 0.801.…”

Coupling Au-loaded magnetic frameworks to photonic crystal for the improvement of photothermal heating effect in SERS

“…These will probably limit their extensive application in SERS. Many studies 41–43 have reported that Au-PC, which is prepared by doping plasmonic Au NPs into the voids of opal PC, acts as a traditional hybrid SERS substrate. The highly facile method of vertical deposition is conducive due to the lack of any need for hazardous reagents, and thus, Au-PC has received wide attention.…”

A Robust Method for the Elaboration of SiO2-Based Colloidal Crystals as a Template for Inverse Opal Structures

“…In particular, owing to its simple fabrication methods, colloidal PCs (C-PC) made from monodisperse nanoparticles have been employed in coatings [ 6 , 7 , 8 ], films for surface-enhanced Raman scattering [ 9 ], chromatographic columns packing [ 10 , 11 ], and reflectometric interference spectroscopy [ 12 , 13 , 14 ]. Additionally, C-PCs have been studied as sacrifice templates to create inverse opals (IO) employing inorganic, organic, metallic, and ceramic materials, which are exact inverse replicas of C-PC structures and therefore maintain their optical properties [ 15 ].…”