title: A method for the detection of alcohol vapours based on optical sensing of magnesium 5,10,15,20-tetraphenyl porphyrin thin film by an optical spectrometer and principal component analysis.
abstract: In this work we have proposed a method for the detection of alcohol vapours, i.e. methanol, ethanol and isopropanol, based on the optical sensing response of magnesium 5,10,15,20-tetraphenyl porphyrin (MgTPP) thin films, as measured by optical spectrometry with the assistance of chemometric analysis. We have implemented a scheme which allows a laboratory UV-vis spectrometer to act as a so-called "electronic nose" with very little modification. MgTPP thin films were prepared by a spin coating technique, using chloroform as the solvent, and then subjected to thermal annealing at 280°C in an argon atmosphere. These MgTPP optical gas sensors presented significant responses with methanol compared to ethanol and isopropanol, based on the dynamic flow of alcohol vapours at the same mol% of alcohol concentration. Density functional theory (DFT) calculations were performed to model the underlying mechanism of this selectivity. The performance of the optical gas sensors was optimised by varying the fabrication parameters. It is hoped that the MgTPP thin film together with an off-the-shelf optical spectrometer and a simple chemometrics algorithm can be a valuable tool for the analysis of alcoholic content in the beverage industry.
authors.affiliation: Department of Physics and Center of Nanoscience and Nanotechnology, Faculty of Science, Mahidol University, Bangkok 10400, Thailand.
authors.forename: Sumana
authors.initials: S
authors.lastname: Kladsomboon
authors.forename: Teerakiat
authors.initials: T
authors.lastname: Kerdcharoen
mesh_terms: D019840:2-Propanol / Q000032:analysis; D000438:Alcohols / Q000032:analysis*; D000431:Ethanol / Q000032:analysis; D005740:Gases / Q000032:analysis*; D008274:Magnesium / Q000737:chemistry*; D008665:Metalloporphyrins / Q000737:chemistry*; D000432:Methanol / Q000032:analysis; D018625:Microscopy, Atomic Force; D011166:Porphyrins / Q000737:chemistry*; D025341:Principal Component Analysis; D013056:Spectrophotometry, Ultraviolet
chemical_list: C509964:5,10,15,20-tetraphenylporphyrin; D000438:Alcohols; D005740:Gases; D008665:Metalloporphyrins; D011166:Porphyrins; D000431:Ethanol; D008274:Magnesium; D019840:2-Propanol; D000432:Methanol