| In biological systems,some cations,anions and biological molecules involve in a variety of physiological or pathological processes.In order to study and understand their roles and influences in physiology and pathology,the development of effective detection methods has become a research hotspot.Among them,fluorescent probe has gotten a lot of attention due to its high sensitivity,non-destructive sample preparation,and fast analysis with high spatiotemporal resolution,which is widely used in analytical chemistry,biochemistry,biology and medicine.In this thesis,we designed and synthesized a series of fluorescent probes based on benzothiazole and naphthalene derivatives for detection of biological-related hydrogen ion and molecules.The contents of this thesis are presented as follows:1.In Chapter 1 the fluorescent probe for thiols was designed and synthesized based on modulation of the excited-state intramolecular proton transfer?ESIPT?process of 2-?2'-hydroxy-4'-diethylaminophenyl?benzothiazole.In the absence of Cys or GSH,probe 1 exhibits weak fluorescence because of the strong quenching effect of the nitro group.Upon the addition of Cys or GSH in neutral solution containing cetyltrimethylammonium bromide micelles,the dinitrophenyl group of the probe is removed via the thiolysis of dinitrophenyl ether,thereby retrieving the ESIPT process of2-?2'-hydroxy-4'-diethylaminophenyl?benzothiazole,whichresultsina fluorescence enhancement at 423 nm.The probe exhibited high sensitivity towards thiols including cysteine and glutathione,with a detection limit of 8.4×10-8 M for cysteine and 8.0×10-9 M for glutathione.2?In cellular biology,p H plays vital role in many biologicalprocess.Abnormal intracellular p H values result in cellular dysfunction and cause some serious diseases such as cancer and Alzheimer's disease.Therefore,monitoring intracellular p H changes is very critical for the diagnosis of certain diseases and the measurement of therapeutic efficiencies.In Chapter 2 a novel acidic p H fluorescent probe 1 based on a benzothiazole derivative has been synthesized.The linear response range covers the acidic p H range from 3.44 to 6.46.The fluorescence enhancement of the studied probe1 with an increase in hydrogen ions concentration is based on the hindering of enhanced photo-induced electron transfer?PET?process.Moreover,the p H probe possesses a highly selective response to H+in the presence of metal ions,anions and other bioactive small molecules which would be interfere with its fluorescent p H response.3?So far most fluorescent dye have been used for designing one-photon fluorescent probe.Two-photon microscopy?TPM?,which excites a two-photon?TP?fluorophore by two photons with lower energy can provide better three-dimensional spatial localization,and observe biological events inside tissues with increased depth?>500?m?.In chapter 3,we designed and synthesized a new TP bioimaging probe 1for thiophenols by employing a D-?-A-structured naphthalene derivative.The probe can be applied to the quantification of thiophenols with a linear range covering from2.0×10-8 to 7.0×10-6mol?L-1.It exhibited a high selectivity and excellent sensitivity with a detection limit of 9.6 n M.Moreover,it was successfully used for practical detection of thiophenol in water samples and two-photon imaging of thiophenol in live cells and tissues at a depth of 40–155?M... |
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