title: Poly(p-phenyleneethynylene)-based tongues discriminate fruit juices.
abstract: We describe a simple optoelectronic tongue, consisting of a positively charged, fluorescent poly(para-phenyleneethynylene), P2, that reacts to fruit juices, when employed at three different pH-values (pH 3, 7, 13). This minimal tongue identifies and discriminates 14 different commercially available apple juices, 6 different grape juices and 5 different black currant juices from each other. A similar, negatively charged fluorescent polymer, P1, also achieved discrimination, but the analyte concentration had to be increased by a factor of 50. A mixture of black currant juice and red grape juice is identified as red grape juice, for specific combinations of grape and black currant juices. A mixture of red and green grape juice passes as red grape juice in our sensing system when it contains more than 70% of red grape juice. The data were obtained by fluorescence quenching of the conjugated polymers and processed by linear discriminant analysis of the collected data.
authors.affiliation: Organisch-Chemisches Institut, Ruprecht-Karls-Universität Heidelberg, Im Neuenheimer Feld 270, 69120 Heidelberg, Germany.
authors.forename: Jinsong
authors.initials: J
authors.lastname: Han
authors.affiliation: Organisch-Chemisches Institut, Ruprecht-Karls-Universität Heidelberg, Im Neuenheimer Feld 270, 69120 Heidelberg, Germany.
authors.forename: Benhua
authors.initials: B
authors.lastname: Wang
authors.affiliation: Organisch-Chemisches Institut, Ruprecht-Karls-Universität Heidelberg, Im Neuenheimer Feld 270, 69120 Heidelberg, Germany.
authors.forename: Markus
authors.initials: M
authors.lastname: Bender
authors.affiliation: Organisch-Chemisches Institut, Ruprecht-Karls-Universität Heidelberg, Im Neuenheimer Feld 270, 69120 Heidelberg, Germany.
authors.forename: Kai
authors.initials: K
authors.lastname: Seehafer
authors.affiliation: Organisch-Chemisches Institut, Ruprecht-Karls-Universität Heidelberg, Im Neuenheimer Feld 270, 69120 Heidelberg, Germany and CAM, Centre for Advanced Materials, Ruprecht-Karls-Universität Heidelberg, Im Neuenheimer Feld 225, 69120 Heidelberg, Germany. uwe.bunz@oci.uni-heidelberg.de.
authors.forename: Uwe H F
authors.identifier: http://orcid.org/0000-0002-9369-5387
authors.initials: UH
authors.lastname: Bunz
mesh_terms: D000480:Alkynes; D062609:Electronic Nose; D004987:Ethers; D000067030:Fruit and Vegetable Juices / Q000032:analysis*; D027845:Malus; D027843:Vitis
chemical_list: D000480:Alkynes; D004987:Ethers; C436384:phenyleneethynylene