| Detecting cations is of great importance in analytical or bioanalytical chemistry because of their significant importance in biological, environmental and medical filelds. Among the numerous analytical methods that are available for the detection of cations, flame photometry, atomic absorption spectrometry, ion sensitive electrodes, electron microprobe analysis, neutron activation analysis, etc., are expensive, often require samples of large size and do not allow continuous monitoring. In contrast, the methods based on fluorescence offer distict advantages in terms of sensitivity, selectivity, response time, on-line detection. Therefore, a large number of fluorescent sensors have been designed for cations sensing.As an important complementary method of fluorescence sensing, room temperature phosphorimetry has been proved to be powerful for optical sensing due to its large Stokes shift, high signal-to-noise ratio, good selectivity, and especially long triplet lifetimes etc. If the sensory emission is long lived, the sensor signal can be more easily time-resolved from the background noise caused by the matrix autofluorescence and light scattering. So sensors with long lifetimes have important advantages in medical, biological assays. However, there is much less reports on phosphorescent sensors for cations. So, we aimed at designing phosphorescent sensors for cations detection in aqueous solution in this paper.Usually it is necessary to carry out deoxygenation procedure before RTP sensing, which is inconvenient and limits the application of RTP method more or less. In the second part of this paper, we mainly studied anti-oxygen-quenching RTP.In the first part of this dissertation, the latest research progress in recent years on the development of supramolecular fluorescent /phosphorescent sensors for cations recognition is reviewed; two different RTP sensors forproton and metal cations are designed.In the second part of this dissertation, the researching background of anti-oxygeon-quenching RTP was discussed and cholate salts, a kind of biological detergent, were introduced with regard to their micelle properties and potential applications in luminescence analysis.The major contents in this dissertation are described as follows:1. According to the principle of photoinduced electron transfer (PET), five aminomethylbromonaphthalene phosphoroionophores with long lifetimes (to ms) were synthesized, all of them working well in (3-cyclodextrin (P-CD) aqueous solutions. They form a family of phosphorescent sensors with pH-dependent spectral properties. For all the compounds, the fully protonated form exhibits the highest phosphorescence emission intensity and the proton-free form of the sensor is weakly emissive due to the designed PET process. The proton-induced phosphorescence enhancement (PEH+) for 1~5 were 70, 16, 40, 14 and 138 respectively. The sensors also show the expected pH dependence of phosphorescence quantum yields. Responses of the sensors can be tuned by variation of substituent.2. A novel phosphorescent sensor, bromonaphthyl iminodiacetic acid (BNIA), is synthesized from the reaction of l-bromo-2-bromomethyl naphthalene with diethyl iminodiacetate. Room temperature phosphorescence (RTP) sensing is carried out in |3-cyclodextrin (J3-CD) aqueous solution. The RTP intensity depends on the acidity and the maximal value is obtained at pH 5.3. The quenching effect is observed with the addition of heavy metal ions due to photoinduced electron transfer process. The quenching ability is estimated by the Stern-Volmer method, and the detection limits of Cu2+, Pb2+, Co2+, Ni2+ are 0.017, 0.024, 0.090 and 0.018 ^mol L"1 respectively (S/N=3). The precision is evaluated as the relative standard deviation (RSD) in five replicates of a sample containing 10 nmol L'1 of four chosen HM ions, and the results are all small than 2%. The system could be potentially used for rapid... |
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