Fish freshness detection by a computer screen photoassisted based gas sensor array

Multi-element gas sensor based on surface plasmon resonance: recognition of alcohols by using calixarene films

“…At the same time, penthanol cannot be practically recognized. Thus, after the performed experiments one can draw the following conclusions: i) thermally deposited calixarene C [4]Re, С [8]А and С [6]А films demonstrate different sensitivity when adsorbing ethanol, isopropanol and penthanol molecules; ii) С[4]А films do not pronounce any noticeable sensitivity to the studied analytes, therefore the respective curves were not presented in this paper; iii) even using two films -C [4]Re and С[8]А -one can distinguish ethanol and isopropanol as well as determine their concentration.…”

“…Being based on the experimental results of serial measurements of the SPR response corresponding to C [4]Re, С [8]А and С [6]А films adsorbing isopropanol, ethanol and penthanol molecules, one can perform a recognition procedure by application of any mathematical classification method, for example, use statistic methods or neuron networks. To estimate the capability of the chosen array in recognition of the studied alcohols, it is necessary to represent amplitude values of the obtained SPR responses in n-dimensional space of sensors and consider distances between them.…”

“…In this work, as sensitive materials of a multisensor array we investigated thin calixarene films: tretbutyl-calix [4,6,8] The thickness of the order of 100 nm was chosen as optimal, because this calixarene film thickness provides the shift of the SPR angle to the range 55 -60°, which is suitable to the chosen prism dimensions. Since this class of calixarene films is thermally stable, the films were deposited using thermal evaporation in vacuum without heating the substrate (ВУП-4 facility, residual vapor pressure 4⋅10 -4 Pa, speed of sputtering 1 nm/s).…”

“…To demonstrate operation of the multi-element sensor based on SPR phenomenon, we used a chip containing four calixarene films: tret-butylcalix [4,6,8]…”

Analysis of Urinary Porphyrins by High Performance Liquid Chromatography-Electrospray Ionization Mass Spectrometry

“…The compounds are regularly and prominently investigated in all known macrocyclic ring systems. [1][2][3][4] Various porphyrins and related molecules are derived from the porphine framework, which contains four pyrrolic subunits linked via four methyne bridges. [2] Excessive production, accumulation, and excretion of porphyrins often result from metabolic aberration.…”