Xiangqian Li,Jiapei Gu,Zhan Zhou,Lufang Ma,Yiping Tang,Jinwei Gao,Qianming Wang
The generation of novel optical sensing structures through the lanthanide coordination has been a key scientific endeavor. The design of molecular indicator for chemical response is derived from the assembly of a polymeric-based ternary europium (III) complex system (Eu(NTA) 3 L/PVA (NTA = 4,4,4-trifluoro-1-(naphthalen-2-yl)butane-1,3-dione, L = 2-(4-(4-(allyloxy)phenyl)-6-(pyridin-2-yl)pyridin-2-yl)pyridine, PVA = poly(vinyl acetate)). The electrospinning technique has been employed to create a nanometer scale membrane and this functional film with ultrafine fibers (diameter of about 110 nm) exhibits intense red light at 618 nm under ultra-violet excitation of 340 nm. The luminescent signal transduction involves the interaction of hydrogen chloride (HCl) with the organic ligand. The strong acidity of the analyte induces dissociation of complex network and the evolution of emission from red to blue has been observed. The fabricated nanosensor demonstrates rapid response time (<2 s) and the detection limit has been calculated to be 3.0 ppm. This effective strategy for achieving lanthanide complex-encapsulated polymer fibers will contribute to the development of new intelligent photonic devices.
Zhan Zhou,Qianming Wang,Jintai Lin,Yanna Chen,Chuqin Yang
Herein, a novel fluorescent indicator for the real-time monitoring of amines is described. This probe contains a complex of europium-(thenoyltrifluoroacetone) 3 (Eu(TTA) 3 ) that efficiently reacts with primary and secondary amines. The electron-withdrawing trifluoroacetyl undergoes a nucleophilic addition with amines, and the complex was used to selectively detect BuNH 2 and Et 2 NH (quenching concentration for BuNH 2 : 10 −4 m , for Et 2 NH: 1.2 × 10 −3 m ) by monitoring emission; no changes were observed in the emission spectrum of Eu(TTA) 3 in the presence of Et 3 N, [Bu 4 N]Cl, or PhNH 2 in aqueous solution (THF/H 2 O = 1:1). The ratio of emission intensity to amine concentration was linear by the least-squares fitting method.
Heterostructured chemosensors have excellent chemical stability, low contamination and excellent recyclability, and are regarded as a promising new generation of sensors with critical properties related to their sensing sensitivity and selectivity. Our preparation strategy for a heterostructured sensor is to construct it using a luminescent lanthanide complex and metal organic framework (MOF). A heterogeneous sensor is systematically produced using EuTTA and ZIF-8 to cover silica, and thin particles are obtained with small size and uniform morphology. Then, the particles were used as a highly selective and sensitive sensor to detect Cu2+ in aqueous solution. Eventually, we find that the well-structured silica@EuTTA@ZIF-8 microspheres have a good fluorescence stability, low detection limit and broad linear range in aqueous environments. These excellent properties make it a potential chemosensor for sensing of Cu2+ in environmental or biological solution systems.
In our work, we achieve the multi-component assembly of novel kinds of photofunctional hybrid materials with polyoxometalates (POMs, Na 9 EuW 10 O 36 ·32H 2 O (EuW 10 O 36 9 - denoted as EuW10)) and benzoate (4-aminobenzoate, 4-hydroxybenzoate, 4-mercaptobenzoate) modified mesoporous silica through imidazolium ionic liquid (IL, 1-methyl-3-(trimethoxysilylpropyl) compound as double functional linkage. Using Pluronic P123 surfactant as a template, benzoate functionalized SBA-15 mesoporous host is synthesized as result of the co-condensation of tetraethoxysilane (TEOS) and benzoate modified siloxane as precursor. We fabricate POM into the framework of functionalized SBA-15 mesoporous silica with IL. Here IL behaves as double linkage, which both interact with PMO with electrostatic force through ion exchange and form covalent bond to the functionalized SBA-15 mesoporous silica through its alkoxy group after cohydroxylysis and copolycondensation process. Tb 3+ is further introduced into the above hybrid system through coordination bond to carboxylate group of benzoate unit, which can be expected to modify luminescence color and to obtain close white luminescence. The physical characterizations prove these hybrid materials possess high surface area, uniform mesoporous structure, good crystallization and relatively excellent luminescence properties.