Facile synthesis of rhodamine-based highly sensitive and fast responsive colorimetric and off-on fluorescent reversible chemosensors for Hg2+: preparation of a fluorescent thin film sensor

Abstract

Fluorescence-active chemosensors (L1-L4), comprising a rhodamine scaffold and a pseudo azacrown cation-binding subunit, have been proposed and characterized as a fluorescent chemosensor for Hg(2+). An on-off type fluorescent enhancement was observed by the formation of the ring-opened amide form of the rhodamine moiety, which was induced by the interactions between Hg(2+) and the chemosensor. Upon the addition of Hg(2+), an overall emission change of 350-fold was observed, and the selectivity was calculated to be 300 times higher than Cu(2+) for receptors L2-L4. A polymeric thin film can be obtained by doping poly(methyl methacrylate) or PMMA with chemosensor L2. Such a thin film sensor can be used to detect Hg(2+) with high sensitivity and can be recovered using diluted NaOH.

Optical methods for the detection of heavy metal ions

“…analogous sensors described above), and after the addition of mercury ions, ring opening occurs to give the acyclic amide form, resulting in a 350-fold fluorescence enhancement (band maximum at 580 nm). 109 Copper(II) cations induce a similar response but the sensitivity to mercury is 300 times higher.…”

Spray coating thin polymeric sensor films for Au3+

“…The calculation of optimized geometries and the HOMO, LUMO energies of the PSS‐Rho4 and the PSS‐Rho4 + Au 3+ complex were performed with 2:1 stoichiometry by using the DFT method at the B3LYP/6‐31(d) theoretical level under the Gaussian 09 program . The calculated results showed that PSS‐Rho4 can form stable complex with Au 3+ through favorable cation–dipole interactions from the oxygen atoms of two acyclic lactam groups and the oxygen atoms of two sulfonate group.…”

“…Figures and show the color and fluorescence changes after treatment with Au 3+ ions at concentrations between 1.0 × 10 −3 and 1.0 × 10 −6 M. The results showed that upon increasing the concentration of Au 3+ ions on the hybrid sensor materials, the increases of the color and fluorescence intensities were also observed, as expected. After treatment with an aqueous EDTA solution under basic condition, the color change of PSS‐Rho4 in aqueous solution was found to be reversible as the pink color of the complex disappear (Figures and ). From the SEM image [Figure (b)] of PSS‐Rho4 ‐filtered paper, it can be seen that the integrity of the cellulose fiber was not degraded by the modification.…”

“…For example, an acidic pH can usually activate a nonfluorescent rhodamine spirolactam to be a highly fluorescent rhodamine derivative . Recently, rhodamine‐based sensors for cations and other analytes have received ever‐increasing interest in areas such as sensors for Pb 2+ , Cu 2+ , Hg 2+ , Fe 3+ , Cr 3+ , Au 3+ , NO, and OCl − . Our research expands expertise and knowledge in a rhodamine B derivative synthesis that can help to design and develop chemosensors based on rhodamine B derivative …”

Novel Multifunctional Luminescent Electrospun Fluorescent Nanofiber Chemosensors-Filter and Their Versatile Sensing of pH, Temperature, and Metal Ions

“…Exposure to methylmercury can lead to Minamata disease, the typical symptoms of which are sensory disturbances (glove and stocking type), ataxia, dysarthria, constriction of the visual field, auditory disturbances, and tremors in some cases [1][2][3]. Therefore, selective and sensitive chromogenic or fluorogenic chemosensors for various HTM cations detection [4][5][6][7][8] have been designed to solve the aforementioned issues.…”