4 research outputs found
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No full textThe donor–acceptor (D–A) type dipolar fluorophores, an important class of luminescent dyes with two photon absorption behaviour, generally emit strongly in organic solvents but poorly in aqueous media. To understand and enhance the poor emission behaviour of dipolar dyes in aqueous media, we undertake a rational approach that includes a systematic structure variation of the donor, amino substituent of acedan, an important two-photon dye. We identify several factors that influence the emission behaviour of the dipolar dyes in aqueous media through computational and photophysical studies on new acedan derivatives. As a result, we can make acedan dyes emit bright fluorescence underone- and two-photon excitation in aqueous media by suppressing the liable factors for poor emission: 1,3-allylic strain, rotational freedom, and hydrogen bonding with water. We also validate that these findings can be generally extended to other dipolar fluorophores, as demonstrated for naphthalimide, coumarin and (4-nitro-2,1,3-benzoxadiazol-7-yl)amine (NBD) dyes. The new acedan and naphthalimide dyes thus allow us to obtain much brighter two-photon fluorescent images in cells and tissues than in their conventional forms. As an application of these findings, a thiol probe is synthesized based on a new naphthalimide dye, which shows greatly enhanced fluorescence from the widely used N,N-dimethyl analogue. The results disclosed here provide essential guidelines for the development of efficient dipolardyes and fluorescence probes for studying biological systems, particularly by two-photon microscopy.14
<i>C</i><sub>3</sub>-Symmetric Cage-like Receptors: Chiral Discrimination of α-Chiral Amines in a Confined Space
No full text<i>C</i><sub>3</sub>-Symmetric Cage-like Receptors: Chiral Discrimination of α-Chiral Amines in a Confined Space
No full textCage-like receptors that have internal binding sites and a C3-symmetric chiral bias have been synthesized, and their chiral discrimination behavior toward α-chiral amines as their ammonium salts has been compared with that of their open structures
Reaction-based two-photon probes for in vitro analysis and cellular imaging of monoamine oxidase activity
No full textReaction-based fluorescent probes for monoamine oxidases A and B are developed based on a new two-photon absorbing compound and its precursor. The probes show turn-on fluorescence response to the enzymes owing to the two-photon absorbing compound produced by the enzymatic activity, as monitored by one-as well as two-photon microscopy for the first time.X114341sciescopu
