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Examines the use of phosphorescence and optical detection of magnetic resonance in determining the triplet state of diamidino-phenyl indole (DAPI). Alteration of biomolecular processes of DNA; Structure of the dication of DAPI; Characterization of DNA complex.

Examines the characterization of tryptophan residues of Escherichia coli alkaline phosphatase. Phosphorescence and optically detected magnetic resonance of tryptophan; Decay kinetics of tryptophan; Interactions with polar residues.

Examines the effects of nucleic acid binding on the triplet state properties of tetrapeptides containing tryptophan and 6-methyltryptophan. Use of phosphorescence and optically detected magnetic resonance spectroscopy; Account on the binding of poly(A) or poly(U) nucleic acids to tetrapeptides; Details on limiting types of tryptophan-base interaction.

A pyrene based fluorescent probe, 3-methoxy-2-((pyren-2yl-imino)methyl)phenol (HL), was synthesized via simple one-pot reaction from inexpensive reagents. It exhibited high sensitivity and selectivity toward Al3+ over other relevant metal ions and also displayed novel aggregation-induced emission enhancement (AIEE) characteristics in its aggregate/solid state. When bound with Al3+ in 1:1 mode, a significant fluorescence enhancement with a turn-on ratio of over ~200-fold was triggered via chelation-enhanced fluorescence through sensor complex (Al-L) formation, and amusingly excess addition of Al3+, dramatic enhancement of fluorescence intensity over manifold through aggregate formation was observed. The 1:1 stoichiometry of the sensor complex (Al-L) was calculated from Job's plot based on UV-vis absorption titration. In addition, the binding site of sensor complex (Al-L) was well-established from the ¹H NMR titrations and also supported by the fluorescence reversibility by adding Al3+ and EDTA sequentially. Intriguingly, the AIEE properties of HL may improve its impact and studied in CH3CN-H2O mixtures at high water content. To gain insight into the AIEE mechanism of the HL, the size and growth process of particles in different volume percentage of water and acetonitrile mixture were studied using time-resolved photoluminescence, dynamic light scattering, optical microscope, and scanning electron microscope. The molecules of HL are aggregated into ordered one-dimensional rod-shaped microcrystals that show obvious optical waveguide effect. [ABSTRACT FROM AUTHOR]