Fluorescence investigation of model compounds for light-emitting alternating copolymers in heterogeneous environments.
In this paper, the fluorescence spectra of the model compounds M(TPA-PPV) and M(TPA-PAV) of novel light-emitting alternating copolymers, were studied and the effect of KNO3 on the interaction between the model compounds and the ionic micelle-water interface was also investigated. The following is found: (i) the fluorescence changes of M(TPA-PPV) are related to the state of cetyltrimethylammonium bromide (CTAB) and sodium dodecyl sulfate (SDS) solution: (ii) an aggregated state can be formed in M(TPA-PAV) solution at low concentration of CTAB; (iii) higher concentrations of KNO3 may affect the interaction between the model compounds and the ionic micelle-water interface.
A Novel Fluorescence Sensing Mode for Ions and Neutral Molecules Based on Ionic Micelle Mediated TICT Dual Fluorescence
Abstract According to the high sensitivity of TICT (twisted intramolecular charge transfer) emission to external electric field strength, a novel fluorescence sensing mode for ions and neutral molecules in aqueous solution was proposed by using ionic micelle mediated TICT dual fluorescence was proposed. In the sensing system the ionic micelle acts as electric field mediator for the TICT fluorophore. Examples were given for sensing potassium nitrate, sodium dodecylsulfate, and β-cyclodextrin by using sodium p-diethylaminobenzoate(SDEAB)/cetyltrimethylammoinum bromide(CTAB) micelle sensing system. Linear response of dual fluorescence intensity ratio Ia/Ib to analyte concentration with correlation coefficient higher than 0.99 was observed for three analytes.
Fluorimetric determination of scandium using the cyclodextrin-1,4-dihydroxyanthraquinone inclusion complex
Quinizarin (1,4-dihydroxyanthraquinone) and β-cyclodextrin (β-CD) form a 1 : 1 inclusion complex with an estimated association constant of 200 l mol–1 at pH 7.1. The hydrophobic nature of β-CD helps to dissolve and stabilise the dye and hence permits its use as a ligand in coordination reactions with metal ions. This inclusion compound has been used for the fluorimetric determination of trace amounts of scandium. A limit of detection of < 1 ng ml–1 of scandium was obtained with a relative standard deviation of 5%. The method was free from interferences from 40 species tested at concentration ratios below 1 : 1 m/m.