Discrimination of Methanol and Ethanol Vapors by the Use of a Single Optical Sensor with a Microporous Sensitive Layer

Abstract

The sorption of methanol and ethanol vapors by a microporous glassy polycarbonate is studied. The increase of the refractive index of the polymer during analyte sorption is measured by surface plasmon resonance. Both analytes are sorbed into the micropores of the polymer showing different diffusion kinetics. The sensor response during analyte exposure is subdivided into different time channels. By evaluating this additional data dimension by neural networks, a simultaneous multicomponent analysis of binary mixtures of ethanol and methanol vapors is possible using the sensor response of only one single sensor. A feature extraction results in an interpretable model and an improved prediction with errors of 2.0% for methanol and 2.4% for ethanol.

Development of a sensitive gas sensor by trapping the analytes on nanomaterials and in situ cataluminescence detection

“…The development of sensitive sensors is significantly important due to the great demands in many areas such as environmental monitoring, domestic safety, public security, and food industries [1][2][3][4]. Improvement of sensitivity can be achieved by increasing the sensitivity of the sensing element itself, or by preconcentrating the sample before detection [5][6][7].…”

Spider Silk as an Active Scaffold in the Assembly of Gold Nanoparticles and Application of the Gold–Silk Bioconjugate in Vapor Sensing

“…Chemical sensors have been pursued as an active area of research for a long time and, in particular, methanol sensors have been of major interest for a long time in the alcohol industry. Various methods have been applied to detect methanol in air or solution, such as HPLC,15 membrane induction mass spectrometry (MIMS),16 fluorescence17 and optical techniques,18 quartz crystal microbalance (QCM),19 and electrical‐conductivity‐based methods 20. It is well known that spider silk responds to changes in the local environment and contracts to varying extents depending on the polarity of the solvent to which the fibers are exposed.…”

Visual Sensor for Sterilization of Polymer Fixtures Using Embedded Mesoporous Silicon Photonic Crystals

“…This can be expected to give a strong reflectance spectrum that is more readily seen by eye when the sensor is wetted with the disinfectant solution; for example, if the porous skeleton possesses a refractive index closely matching the value of the liquid disinfectant filling the pores, then the intensity of the stop band reflectance will be near zero. The index of refraction of crystalline silicon in the wavelength range of interest is 3.8, 33 while the index of polycarbonate (1.58) 35 is closer to the index of 70% aqueous isopropanol (1.372 ± 0.001 at 22.6 °C, measured at λ = 589.3 nm) used as a disinfectant. Thus, we attempted to build a sensor element where only a small portion of the pSi film was infiltrated with polymer, in order to serve as an anchoring point, while the majority of the pSi layer remained open and exposed on the fixture surface to act as the sensor (Scheme 1).…”