The Preparation And Properties Of A New Self-Assembled Fluorescent Chemosensor Based On Thiacalixarenes

A new ON-OFF fluorescent chemosensor for Cu2+ion was prepared throughself-assembly inside surfactant micelles of p-tert-butylthiacalix[4]arene (TCA) andphosphor in water solution. Ultraviolet absorption spectrum had prove that the phosphorand TCA has been loaded into the surfactant micelles, so that self-assembly process wasrealized.Several influence factors such as the quantity of TCA, the concentration ofphosphor and surfactant, the pH value, the compossible interference ion, wereinvestigated for the systematical study on the measuring capacities of the fluorescentchemosensor for Cu2+ion. It was shown that the phosphor concentration in10-7mol/Lorders of magnitude, respectively, the concentration of the surfactant is sodium dodecylsulfate (SDS)150mmol/L, sodium dodecyl benzene sulfonate (SDBS)50mmol/L, dodecyl trimethyl ammonium bromide (DTAB)600mmol/L, myristyltrimethyl ammonium bromide (TTAB)250mmol/L, tritonX-100(TX-100)200mmol/L,SDS, SDBS, DTAB, TTAB, TX-100micellar system corresponding to the TCAconcentrations are2,2,6,7,4.95×10-4mol/L, the pH value is8.0, can Cu2+ion be detectedpreferably by the fluorescent chemosensor, and the concentrations of Cu2+ions can bealmost linearly measured according to the fluorescence quenching in a certain range inspite of the coexistence of a variety of metal cations and anions in the solution. TCAcould obviously reduce the aggregation numbers of empty micelles. Using referencemethod to measure and calculate the the fluorescent quantum yield of the phosphor ofthe fluorescent chemosensor and through the analysis of the I1/I3of pyrene to measurethe change of the polarity of the micro environment of phosphor. It was found that thesurfactant micelles can significantly increase the the fluorescent quantum yield ofphosphor and reduce the polarity of the micro environment around phosphor, theaddition of TCA have almost no effect on the polarity of the micro environment insidemicelles and the fluorescent quantum yield of phosphor. Changing the type of phosphor and adjusting excitation and detection wavelength to investigate the relationshipbetween phosphor and the detection performance of the fluorescent chemosensor.Results indicated that for the photon energy of the fluorescence of phosphor within therange of3.061~3.179eV, thiacalixarenes based self-assembled fluorescentchemosensors composed of this phosphor have a more sensitive Cu2+ion detectioneffect.