title: Fluorescent Molecular Rotor-in-Paraffin Waxes for Thermometry and Biometric Identification.
abstract: Novel thermoresponsive sensor systems consisting of a molecular rotor (MR) and paraffin wax (PW) were developed for various thermometric and biometric identification applications. Polydiphenylacetylenes (PDPAs) coupled with long alkyl chains were used as MRs, and PWs of hydrocarbons having 16-20 carbons were utilized as phase-change materials. The PDPAs were successfully dissolved in the molten PWs and did not act as an impurity that prevents phase transition of the PWs. These PDPA-in-PW hybrids had almost the same enthalpies and phase-transition temperatures as the corresponding pure PWs. The hybrids exhibited highly reversible fluorescence (FL) changes at the critical temperatures during phase transition of the PWs. These hybrids were impregnated into common filter paper in the molten state by absorption or were encapsulated into urea resin to enhance their mechanical integrity and cyclic stability during repeated use. The wax papers could be utilized in highly advanced applications including FL image writing/erasing, an array-type thermo-indicator, and fingerprint/palmprint identification. The present findings should facilitate the development of novel fluorescent sensor systems for biometric identification and are potentially applicable for biological and biomedical thermometry.
authors.affiliation: †School of Applied Chemical Engineering, Polymer Science and Engineering, Kyungpook National University, 1370 Sankyuk-dong, Buk-ku, Daegu 702-701, Korea.
authors.forename: Young-Jae
authors.initials: YJ
authors.lastname: Jin
authors.affiliation: ‡School of Applied Chemical Engineering, Applied Chemistry, Kyungpook National University, 1370 Sankyuk-dong, Buk-ku, Daegu 702-701, Korea.
authors.forename: Rubal
authors.initials: R
authors.lastname: Dogra
authors.affiliation: ‡School of Applied Chemical Engineering, Applied Chemistry, Kyungpook National University, 1370 Sankyuk-dong, Buk-ku, Daegu 702-701, Korea.
authors.forename: In Woo
authors.initials: IW
authors.lastname: Cheong
authors.affiliation: †School of Applied Chemical Engineering, Polymer Science and Engineering, Kyungpook National University, 1370 Sankyuk-dong, Buk-ku, Daegu 702-701, Korea.
authors.forename: Giseop
authors.initials: G
authors.lastname: Kwak
mesh_terms: D056667:Biometric Identification / Q000379:methods*; D015374:Biosensing Techniques; D010232:Paraffin / Q000737:chemistry*; D013050:Spectrometry, Fluorescence / Q000379:methods*; D062125:Thermometry / Q000379:methods*; D014885:Waxes
chemical_list: D014885:Waxes; D010232:Paraffin
keywords: biometric identification; molecular rotor; paraffin wax; sensor; thermometry