Feng

A Coumarin-Derived Fluorescence Chemosensors Selective for Copper(II)

Abstract Two different coumarin derivatives have been connected via animine linkage to obtain a new fluorescence signaling system. The coumarin derivative (L) containing a C-N group was designed as an example for illustration. The free ligand L is almost nonfluorescent due to the isomerization of C-N double bond in the excited state. However, in the presence of a Cu(II) ion, this isomerization is stopped because of bonding to the metal ion, resulting in a high-intensity (400-fold) emission. In this way, we designed a new compound for copper-selective and ratiometric chemosensors.

Determination of Lysozyme by Thiol-Terminated Aptamer-Based Surface Plasmon Resonance

ABSTRACT A sensitive and selective surface plasmon resonance (SPR) aptasensor has been developed for the real-time determination of lysozyme. The thiol-terminated lysozyme aptamer was covalently attached to the surface of sensor through Au–S bonding. In the presence of lysozyme, the aptamer captured lysozyme on the surface and enhanced the SPR signal that was proportional to the concentration of lysozyme. Under the optimized conditions, the SPR signal was linear with lysozyme concentration from 1 to 100u2009µmol/L. The detection limit for lysozyme was 0.5u2009µmol/L. The aptasensor also provided high specificity for lysozyme and was unaffected by other proteins. This aptasensor provides rapid, simple, and sensitive determination of lysozyme detection and a promising strategy for other proteins.

A NOVEL CHEMOSENSOR FOR Fe(III) BASED ON PHOSPHORESCENCE QUENCHED 9-BROMOPHENANTHRENE INDUCED BY β-CYCLODEXTRIN COMBINED WITH FLOW INJECTION RENEWABLE DROP

A novel phosphorescent chemosensor for Fe(III) based on room-temperature phosphorescence (RTP) using the method of flow injection renewable drop (FIRD) was developed. A RTP of 9-bromophenanthrene (BrP) can be induced by β-cyclodextrin (β-CD) in the presence of cyclohexane (CH); however, trace Fe(III) caused a decrease of the RTP emission. The optimal conditions were investigated. Under the optimal conditions, the analytical curve of Fe3+ gave a linear dynamic range of 4.0 × 10−7 mol(L−1∼6.0 × 10−4 mol(L−1, with a detection limit of 36 μg/L. When the established CD-RTP method was applied to determine the concentrations of Fe(III) in synthetic samples, the experiment results demonstrated that the range of recovery was 97.3%–102%, with a relative standard deviation less than 2.05% (n = 6).