Fabrication of a fluorescent sensor by organogelation: CdSe/ZnS quantum dots embedded molecularly imprinted organogel nanofibers

We describe a molecularly imprinted polymer (MIP)-based fluorescent sensor fabricated through an organogelation process. The sensor was comprised of a molecularly imprinted nanofiber as a receptor and a CdSe/ZnS quantum dot (QD) as a signal transducer. The sensor fabrication was carried out in three steps: (1) organogelation of a polymerizable gelator (PG) in the presence of the QD and a template, (2) gel-state polymerization and (3) extraction of the template. We chose histamine as a model template. PG had two different polymerizable groups: an acrylate and a diacetylene. As a functional monomer for complexation with the template, an acrylate having a carboxyl group was used. The QD and template-containing organogel formed in n-decane were polymerized in the presence of a photoinitiator and a cross-linker by UV irradiation to produce highly cross-linked organogel nanofibers. The template molecules were removed by extraction with methanol/acetic acid (9:1 v/v) to give the QD-incorporated, histamine imprinted organogel nanofibers (QD-HIOGNF). QD-HIOGNF showed high molecular recognition properties toward histamine in respects to both sensitivity and selectivity. The fluorescence intensity of QD-HIOGNF was quenched sensitively as the concentration of histamine increased. QD-HIOGNF could be reused for sensing after removing the bound analytes. (C) 2016 Elsevier B.V. All rights reserved.