Search

A novel and simple fluorescence probe was synthesized from benzo[1,2- b:4,5- b′]dithiophene (BDT) and trimethylsilylethyne via Sonogashira reaction, and showed highly selective and sensitive fluorescence decreasing response towards F−. The probe molecule turned to a weakly fluorescent terminal alkyne moiety because its trimethylsilyl (TMS) group was cleaved by fluoride, which was proved by 1H NMR titration. Whereas no distinct fluorescent changes were observed with the addition of other anions, such as Cl−, Br−, I−, AcO− and H2PO4−. Upon the addition of F−, the maximum fluorescence emission wavelength shifted from 460 nm to 450 nm with a decrease of fluorescence intensity by 40% within 20 s. Moreover, the detection limit towards F− was calculated to be as low as 73.5 nmol/L. [ABSTRACT FROM AUTHOR]

A novel turn-off probe for copper(II) containing benzo[1,2-b:4,5-b′]dithiophene (BDT) and two picolinamide units was synthesized. In this probe, two picolinamide units complex with one Cu 2+ ion and two nitrogen atoms in each picolinamide unit coordinate with Cu 2+ , which is verified by DFT calculation. Its fluorescence quantum yield is 0.43 and the detection limit is as low as 2.4×10 −8 mol/L. The results show that the probe displays good selectivity for Cu 2+ over other ions (Mn 2+ , Pb 2+ , Cr 3+ , Zn 2+ , Ni 2+ , K + , Ca 2+ , Ag + , Mg 2+ , Fe 3+ , Fe 2+ , Hg 2+ , Al 3+ , Cd 2+ , Pd 2+ , Co 2+ ). Furthermore, the probe induced by Cu 2+ and the π–π interaction of the aromatic unit can also form rod structure assembly, which can be observed by scanning electron microscopy (SEM). [ABSTRACT FROM AUTHOR]