title: Unconventional Nonlinear Input-Output Response in a Luminescent Molecular Switch by Inner Filtering Effects.
abstract: Nonlinear input-output relations are at the basis of the regulation of biochemical processes in living organisms and are important for the development of digital logic circuits based on molecules. In this article we show that a linear change of a chemical input can be translated into an exponential change of a luminescence output in a simple fluorescent acid-base switch based on 8-methoxyquinoline. Such unconventional behavior arises from the fact that part of the light emitted by the switch in its basic form is reabsorbed by the acid form, and is made possible by the particular spectroscopic properties of the two forms. Systems of this kind could act as noise filters in analog-to-digital conversion, and as control elements to increase the functional complexity of artificial molecular devices.
authors.affiliation: Dipartimento di Scienze e Tecnologie Agro-alimentari, Alma Mater Studiorum, Università di Bologna, Viale Fanin 50, 40127, Bologna, Italy.
authors.forename: Massimo
authors.initials: M
authors.lastname: Baroncini
authors.affiliation: Dipartimento di Chimica "G. Ciamician", Alma Mater Studiorum, Università di Bologna, Via Selmi 2, 40126, Bologna, Italy.
authors.forename: Monica
authors.initials: M
authors.lastname: Semeraro
authors.affiliation: Dipartimento di Scienze e Tecnologie Agro-alimentari, Alma Mater Studiorum, Università di Bologna, Viale Fanin 50, 40127, Bologna, Italy.|Istituto ISOF-CNR, Via Gobetti 101, 40129, Bologna, Italy.
authors.forename: Alberto
authors.identifier: http://orcid.org/0000-0003-2546-9801
authors.initials: A
authors.lastname: Credi
mesh_terms: D000703:Analog-Digital Conversion; D006863:Hydrogen-Ion Concentration; D008128:Logic; D049449:Luminescence; D015394:Molecular Structure; D011804:Quinolines / Q000737:chemistry*
chemical_list: D011804:Quinolines
keywords: luminescence; molecular devices; molecular logic; molecular switches; photochemistry