Switching properties of fluorescent photochromic poly(methyl methacrylate) with spironaphthoxazine and D-π-A type pyran-based fluorescent dye.
Fluorescent photochromic poly(methyl methacrylate) (PMMA) with spironaphthoxazine (SPO) and D-π-A type pyran-base fluorescent dye as a fluorophore was synthesized by typical free radical copolymerization. The poly(MMA-co-SPO-co-fluorophore) in both solution and solid film exhibited excellent photoregulated fluorescence switching behavior and reversible modulation of fluorescence intensity using alternating irradiation with UV and visible light. The poly(MMA-co-SPO-co-fluorophore) also showed viscosity and conductivity switching behaviors along with photoresponse.
Chromogenic and fluorescent chemodosimeter for detection of fluoride in aqueous solution.
We have developed a chromogenic and fluorescent chemodosimeter 1 based on the release of resorufin for F- (TBA+ and Na+ salts). This dosimeter 1 displayed drastic dual changes in UV-vis absorption and fluorescence emission intensities selectively for F- over other anions in CH3CN/H2O (50:50, v/v) as well as in acetonitrile.
Electrochemical detection of copper(II) at a gold electrode modified with a self-assembled monolayer of penicillamine
A penicillamine (PCA) self-assembled monolayer (SAM) was prepared on a gold electrode. It has been found that the modified electrode exhibited a selective response to copper ions. As demonstrated by cyclic voltammetric experiments, the SAM-based electrode showed an attractive ability to preconcentrate efficiently traces of copper(II) from solutions. Under optimum conditions, the anodic peak current was proportional to the concentration of Cu(II) in the range from 8.0 × 10−7 to 1.0 × 10−4 M with a detection limit of 4.0 × 10−7 M. Moreover, this modified gold electrode is also characterized by excellent repeatability, showing a relative standard deviation of 3.2% for nine successive measurements of 1.0 × 10−5 M Cu(II). The PCA/Au SAM gold electrode was used for the determination of Cu(II) in a tap water sample and the results showed a good agreement with the data obtained by atomic emission spectrometry.