The Design And Recognition Studies Of Chiral Fluorescent Sensors

Chirality plays an active role in biologically substances in living systems, and subsequently affects the entire life course. At the molecular level, amino acids and monosaccharides constitute the basic units of peptides, proteins and polysaccharides, and chirality is just an inherent nature of such "life skeletons", so life of metabolic and regulatory process usually exhibits sensitivity to stereochemistry, and usually shows different responses to the enantiomers. In the research of the exogenous substances (e.g. drug, pesticide, food additive and purfume materials), chiral recognition becomes an essential factors to consider. Among various techniques used for the detection, fluorescence spectroscopy has emerged as a powerful tool for its many advantageous features like high sensitivity, easy detection and tunability. Fluorescent chemosensors are more and more attractive. Based on the introduction of the new development of the fluorescent recognition mechanism and the applications of fluorescent sesors in chiral recognition, this paper is to start work at focusing on the design, synthesis and research in the polyimine macrocycle fluorescent sensor and the chiral fluorescent senor with the participation of Cu2+.1. The design, synthesis and property studies of the ratiometric fluorescent sensor of Zn2+based on a polyimine macrocycle. We designed and synthesized a new polyimine macrocycle based ratiometric fluorescent chemosensor A1which shows highly selectivity and sensitivity to Zn2+without any interference from other15metal ions. Upon complexation with Zn2+, the solution of A1exhibited a pronounced change in the fluorescence emission spectrum, which shows a character of ratiometric fluorescent sensor. Notably, by using a commercially available UV lamp (λ=365nm), large color changes were observed upon the addition of Zn2+over other metal ions. This work provides a possible way for simple and rapid detection of Zn2+.2. The synthesis of chiral fluorescent sensor and chiral recognition of amino acids with the participation of Cu2+.We designed and synthesized a new fluorescent chemosensor A2which shows highly selectivity and sensitivity to Cu2+without any interference from other13metal ions. Upon complexation with Cu2+, the solution of A2exhibited a pronounced fluorescence quench which shows that it is a outstanding ON-OFF Cu2+fluorescent sensor. After adding Cu2+, the in situ generated Cu2+-containing complex of A2(A2/Cu2+) can exhibit a chiarl recognition to unprotceted chiral α-phenylalanine in polar solution and it shows high specific selectivity and enantioselectivity. Though the enantioselectivity to other chiral a-amino acids is not very good, but further modification of the sensor structure and introduction of more suitable chiral and space structure may ovecome the weakness, and may get both high specific selectivity and enantioselectivity to different chiral a-amino acids.