| Supramolecular chemistry is a novel intersection discipline of chemistry, life science, material science and informatics. Its development is close related to the macrocyclo-chemistry and has been stirring field in recent years. As host molecules of the second and third generation of supramolecular chemistry, cyclodextrins and calixarene with unique structure and function respectively are the current interest hottopic. Recognition and assembly of molecular are the important content of the supramolecular chemistry, especially recognition and sensing of biological molecule and ion. The major contents in this dissertation are described as follows:1. DNA assembling to neutral red (NR) and cyclodextrins (CDs)-NR inclusion complex has been investigated by means of absorption, fluorescence and resonance light scattering (RLS) technique. Depending on the molar ratio R of NR: DNA, the binding of NR with DNA involved in two processes at pH 7.50 and ionic strength 0.0045. The first process occured in R>2.5, where the neutral form of NR with one positive charge was predominant, and DNA was a polyanion. Moreover, enhanced RLS was observed, indicating the aggregation of NR in neutral form on the molecular surface of DNA. The second process occured in R<2.5, where the binding of NR to DNA leaded to extensive NR protonation even at pH 7.50, meanwhile DNA also protonates, and that a protonated NR with two positive charges (the acidic form of NR) could form DNA adducts with a binding mode different from that of the unprotonated form (the neutral form of NR). The results were also illustrated by the CDs-NR supramolecular system. The experimental data showed that NR-CDs decomposed when it bound to DNA. Thus, the decomposed NR was also protonated to form DNA adducts with intercalative mode. In fact, CDs played a role to carry guest molecule to intercalate DNA. A related mechanism is proposed.2. The interactive models of ST with double stranded DNA have been studied by means of the inclusion action of CDs supramolecular system. Through thechanges of absorption, fluorescence and resonance light scattering (RLS) spectra, the intrinsic binding constant (K) and the binding number (n) of ST with DNA and inclusion complexes with DNA was obtained in the case of 20 m mol/L Tris-HCl buffer solution (pH 7.2). According to the experimental results, it could be inferred that the interactive model of ST with DNA was: in low ratio of ST to DNA, the ST must intercalate into DNA and improve the fluorescence quantum yield of ST while in high ratio of ST to DNA, ST interacts with DNA by long range assembly. The small molecules are very important probes for studying the structure and function of nucleic acid, and the results can offer necessary information for understanding the cause of some diseases and curative mechanism of some drugs, especially anticancer ones.3 The formation of the inclusion complex of neutral red (NR) with 4-sulfocalixarene was studied by fluorescence and absorption spectroscopy and the binding constant (K) of the inclusion complexes were obtained. Experimental conditions including concentrations of 4-sulfocalixarene, media acidity and temperature were investigated for the inclusion formation in detail. The results suggested that 4-sulfocalixarene was more suitable for inclusion of the acid form of NR. The complexation thermodynamic parameters indicate that the complexation of NR with 4-solfuocalixarene is mainly driven by the favorable change in enthalpy. The soluble 4-sulfocalixarene has slight hydrophobic function. Electrostatic interaction of the guest's (NR) cationic moiety with sulfonates of the host (4-sulfocalixarene) is the mainly impetus of recognition. The related mechanism is proposed to explain the inclusion process.4. A plasticized poly (vinyl chloride ) optode membrane incorporated with a calix[6]arene hexaester ,a H~+-selective chromoionophore(3,3,'5,5'-tetramethyl-N,N-dibenzylbenzidine, TMB, a novel synthetical cationic dye), and a lipophilic potassium tetrakis (4-chlorophenyl )borate (KTpC1PB) was used as a sensing device for the indirect optical determination of potassium ion. It exhibited a reversible response to potassium ion in pH=4HC1 in the concentration range from l.OxlO'6 to l><10'2 M. The linear range was from 1.53xlO"5 to 3.20* 10"3 M. The proposed optode sensor exhibited a fast response of less than 1 min, good repeatability (n = 7, R.S.D = 3.62 %) at 5xlO"5M, and long-term stability with 92 % of its initial sensitivity after 1 months of storage. The selectivity of the potassium-selective membrane allows its application for detection of potassium concentration in real sample analysis. The result was satisfactory compared with atomic absorption spectrometry (AAS).5. A new calixarene-porphyrin supramolecular sensitizer for zinc ion has been proposed based on the porphyrin fluorescence intensity increasing.In aqueous solution, the fluorescence intensity of meso-tetrakid (4-N-methyl-pyridiniumyl)porphyrin (TMPyP) decreasing by forming a 4-solfuocalixarene-TMPyP inclusion complex. Furthermore, the formation of a supramolecular complex causes a remarkable increase of the porphyrin metalation rate following the porphyrin fluorescence emission increase with increasing the concentration of zinc ion. With the optimum conditions desceibed, The linear range was from 1.0 X 10"6 to 3.5 X 10"5mol/L and the relative standard deviation (R.S.D.) is 2.6% (10 |jl mol/L). The proposed method is simple, rapid and selective and can determinate Zn2+ without organic solevent.6. Using sodium dodecylsulfate as a protective medium, the selective recognition of Cu2+ is realized based on fluorescence quenching of TMPyP. The linear range was from 5.2 X 10~6~ 3.3 X 10"4mol/L. The limit of detection is 7.63 X 10' mol/L (S/N=3), and the precision is evaluated as the relative standard deviation (R.S.D.) in five replicates of a sample containing 10 u, mol/L of Cu2+, and the results is 1.5%. The system could be potentially used for rapid determination of Cu2+in water samples.
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