calix(4)arene and pyrene

A fluorescent calix[4]arene triazole-linked pyrene (CP) was carefully designed and synthesized via click chemistry. The modification of CP with graphene oxide (GO) by a simple non-covalent interaction strategy is presented. Further inspection by electrochemical impedance spectroscopy reveals that the CP-GO could exhibit a very high supramolecular recognition for carbaryl, in particular in serum samples with a nanomolar concentration detection. Additionally, it is easy to directly observe macroscopic recognition by the contact angle, and expand practical applications.

Topics: Calixarenes; Carbaryl; Chemistry Techniques, Analytical; Click Chemistry; Fluorescent Dyes; Graphite; Models, Molecular; Molecular Conformation; Phenols; Pyrenes; Triazoles

A novel calix[4]arene derivative locked in the 1,3-alternate conformation (2) bearing two pyrene and rhodamine fluorophores was synthesized as a selective sensor for the Hg(2+) ion. The sensoring is based on FRET from pyrene excimer emissions to ring-opened rhodamine absorption upon complexation of the Hg(2+) ion. Addition of Hg(2+) to a mixed solution of 2 gave significantly enhanced fluorescence at ∼576 nm via FRET with excitation at 343 nm. We also found that the pyrene excimer emissions formed by the intramolecular π-π interactions are more effective in obtaining strong FRET bands than those by intermolecular π-π interactions.

Topics: Calixarenes; Chemistry Techniques, Analytical; Dimerization; Fluorescence Resonance Energy Transfer; Mercury; Phenols; Pyrenes; Rhodamines; Spectrometry, Fluorescence; Spectrophotometry, Ultraviolet