Design, Synthesis And Performance Study Of Fluorescent Chemosensors Based On Quinoline And Rhodamine

Now, more and more research proves that the amino acids in the body not only as the substrate material of synthetic protein, they can by themselves and their metabolites have the biological activity of regulating role on animal body in many life activities, such as regulating metabolism of nutrients (protein metabolism and lipid metabolism, glucose metabolism, etc.), maintain the body’s homeostasis, affecting the nervous and endocrine, control the basic expression and signal transduction, immune cells, the function such as anti-oxidation, anti-stress, these regulation can eventually affect the organism’s development and health. And these are dependent on the concentration of amino acids in a normal range, concentration above and below normal will become a cause of the disease.A typical example:a higher than normal amount of Cys (19 umol/l), can lead to coronary heart disease, stroke, atherosclerosis, and so on.Therefore, development of amino acid of qualitative and quantitative analysis for detecting technology has very important scientific value and research significance.Fluorescent chemical sensor is different from traditional testing organism biological small moleculescontent detection tools, its high sensitivity, high selectivity, easy synthesis, cheap and good biological characteristics, make its have gradually become the main testing tool in life science and environmental science. It’s more effective to help us to observe and understand the activites from microviews through that researching the reaction between fluorescent chemosensors and bioactive substances. It has been hot studying subject that design and synthesis sensitive and selective organic small-molecule fluorescent chemosensors in bioscience and environmental fields. However, the most of traditional fluorescent chemosensors are one-photon (OP) fluorescent chemosensors. They possess some disadvantages like photobleaching, interference from autofluorescence in cells and tissues, shallow penetration depth (<100μm) and so on, due to their short excitation wavelength and large excitaion energy. On the contrary, two-photon (TP) fluorescent chemosensors have a series of advantages, such as longer excitation wavelength, smaller excitation energy, increased penetration depth (>500 P m), higher spatiotemporal resolution, minimized fluorescence background, and less light scattering and so on. Moreover, two-photon microscope (TPM) imaging could enlarge the observation time in cells and tissues, so that TP fluorescent chemosensors play a important role in researching living activities. In this paper, we design and synthesis quinoline based biothiol TP fluorescent chemosensors and rhodamine B based Pt ions fluorescent chemosensors repectively on the base of consulting much literature. The structures of chemosensors was proved by nuclear magnetic resonance (NMR) spectra and ESI-TOF mass spectra. We also study their property, and use them for bioimaging application with good results. The main research contents are above.1. We design and synthesis the first twisted-intramolecular-charge-transfer (TICT) based two-photon fluorescent chemosensors NQ, which could be used for detecting Cys/Hcy with high selectivity. NQ showed excellent " OFF-ON " fluorescence (at 540 nm) detection signal on addition of Cys/Hcy. The detection mechanism was successfully proved by theoretical calculations, viscosity dependent fluorescence and time resolved fluorescence spectra. NQ exhibits large two-photon absorption (TPA) cross-section with Cys/Hcy (580 and 710 GM) at nearly 800 nm. NQ also expressed nice two-photon bioimaging property.2. Design and synthesis of fluorescent probe RN3 based on FRET mechanism, we can detect Pd2+. Probe have strong fluorescence at 515nm, which fluorescence is emission of coumarin group in molecular. After addition Pd2+, RN3 Palladium ion complexation, rhodamine open loop, coumarin, rhodamine absorbed energy was launched by,515 nm peaks gradually disappear in 575 nm new emission, emission fluorescence fluorescence luodanmingji mission.