Humidity-Resistive Optical NO Gas Sensor Devices Based on Cobalt Tetraphenylporphyrin Dispersed in Hydrophobic Polymer Matrix

Silver nanoparticle polymer composite based humidity sensor.

Silver nanoparticles were synthesised by a chemical reduction process in order to produce an aqueous colloidal dispersion. The resulting colloids were then characterised by a combination of UV-Vis spectroscopy, dynamic light scattering, X-ray diffraction and transmission electron microscopy and the nanoparticles were found to have an average diameter of 20-22 nm. The Ag/polymer nanocomposites w...

Esa Based Fiber Optical Humidity Sensor

Colorimetric and Fluorescent Sensing of SCN- Based on meso-Tetraphenylporphyrin/meso-Tetraphenylporphyrin Cobalt(II) System

An approach for colorimetric and fluorescent sensing of thiocyanate (SCN ) has been proposed based on the competitive-displacement strategy between meso-tetraphenylporphyrin (TPP) and meso-tetraphenylporphyrin cobalt(II) (CoTPP). In THF-water solution, TPP emits strong fluorescence at 651 nm; however, the fluorescence was quenched stepwise by CoTPP, and then restored by SCN , the detection limi...

Optical Fiber Humidity Sensor Based on Lossy Mode Resonances

A novel optical fiber humidity sensor based on lossy mode resonances (LMR) has been developed. LMRs are supported here by a thin Indium Tin Oxide (ITO) coating fabricated onto an optical fiber core via a sol-gel dip coating. ITO coated optical fiber devices present a resonant maximum absorption peak in the infra-red region which is shifted to higher wavelengths when the refractive index of the ...

Optical fiber humidity sensor based on evanescent-wave scattering.

The phenomenon of evanescent-wave scattering (EWS) is used to design an optical-fiber humidity sensor. Porous solgel silica (PSGS) coated on the surface of a silica optical-fiber core scatters evanescent waves that penetrate the coating layer. Water molecules in the gas phase surrounding the optical fiber can be absorbed into the inner surface of the pores of the porous silica. The absorbed wat...