Vapor Responsive One-Dimensional Photonic Crystals from Zeolite Nanoparticles and Metal Oxide Films for Optical Sensing

Abstract

The preparation of responsive multilayered structures with quarter-wave design based on layer-by-layer deposition of sol-gel derived Nb2O5 films and spin-coated MEL type zeolite is demonstrated. The refractive indices (n) and thicknesses (d) of the layers are determined using non-linear curve fitting of the measured reflectance spectra. Besides, the surface and cross-sectional features of the multilayered structures are characterized by scanning electron microscopy (SEM). The quasi-omnidirectional photonic band for the multilayered structures is predicted theoretically, and confirmed experimentally by reflectance measurements at oblique incidence with polarized light. The sensing properties of the multilayered structures toward acetone are studied by measuring transmittance spectra prior and after vapor exposure. Furthermore, the potential of the one-dimensional photonic crystals based on the multilayered structure consisting of Nb2O5 and MEL type zeolite as a chemical sensor with optical read-out is discussed.

Label-Free Vapor Selectivity in Poly(p-Phenylene Oxide) Photonic Crystal Sensors

“…Among these structures, inorganic mesoporous DBRs are interesting thanks to their selectivity (Table 1). 32,35,37,42,43 However, in these systems the spectral…”

Optical Properties of Sol-Gel Nb2O5Films with Tunable Porosity for Sensing Applications

“…The next step of our investigation concerns sensing properties of the samples. Purposely, the reflectance spectra of the samples are measured prior to and after exposure to acetone vapors at relative pressure / 0 = 1 ( 0 is the pressure of saturated vapors at zero degrees) generated from liquid using homemade bubbler system [11]. In order to make a comparison between samples, the exposure time is kept constant for all samples.…”

“…The vapor sensing measurements of the films were implemented in a Cary 05E spectrophotometer equipped with a homemade bubbler system for generation of vapors from liquids with controlled concentrations [11]. Reflectance spectra of the samples were measured before and after exposure to the vapors.…”

“…Mesoporous materials (pore diameter in the range of 2-50 nm) have attracted the scientific interest due to their remarkable properties and potential applications in many advanced areas such as drug delivery systems, sensors, catalysis, photovoltaic cells, and fuel cells [9]. One attractive application of the mesoporous films can be realized when they are incorporated in one-dimensional stacks (Bragg stacks) as high refractive index building blocks [10,11]. In this case, an optical sensing could be realized on the basis of refractive index change due to the condensation of vapors in the pores [12][13][14].…”

Infrared spectroscopic and thermodynamic assessment of extraframework cationic adsorption sites in the zeolite K-L by using CO as probe molecule

“…Besides some applications in heterogeneous catalysis [2][3][4], the 1D topology of its channel system (which displays an ordered array of parallel tubular channels) renders the zeolite K-L an ideal host for M a n u s c r i p t 3 investigating a wide range of phenomena displayed by encapsulated molecules. Among them, single-chain conjugated (conducting) polymers isolated in a dielectric matrix [5], oriented fluorescent dyes [6,7], photochemistry [8,9] and photonic crystals [10], as well as the combined effect of adsorption enthalpy and entropy in the diffusion dynamics of adsorbed molecules [11].…”