An amphiphilic[2]biphenyl-extended pillar[6]arene:Synthesis,controllable self-assembly in water and application in cell-imaging

Synthesis and functionalization of novel macrocyclic host molecules are important topics in supramolecular chemistry.In this work,the first amphiphilic[2]biphenyl-extended pillar[6]arene(AM-[2]BP-ExP6)was designed and synthesized with poly(ethylene glycol)chains as the hydrophilic tails and a rigid cavity as the hydrophobic core.Due to its amphiphilic nature,AM-[2]BP-ExP6 could self-assemble to stable fibers in water.What’s more,AM-[2]BP-ExP6 could associate with quaternary ammonium modified tetraphenylethylene guest(QTPE)to form a 2:1 host-guest complex,accompanied by significant enhanced fluorescence.Interestingly,different like AM-[2]BP-ExP6,AM-[2]BP-ExP6⊃QTPE host-guest complex selfassembled into fluorescent particles with diameter about 310 nm,the obtained fluorescent particles can be further employed in living cell imaging.

Solvents/photo/pillar[5]arene triple responsive morphology and luminescence transformation from an amphiphilic dicyanostilbene-functionalized thiophene

α-Cyanostilbene(CS)based organic luminescent materials with eficient electrical conductivity,aggregation-induced enhanced emission,and controllable multi-colour emission properties,have been aroused wide attention by scientists over the past few years.Self-assembly of cS-motif in aqueous me-dia refers to an environment-friendly method for preparing luminescent materials.However,it is still challenging to control the intrinsic hydrophobic properties of the organic components in aqueous media.In this study,an amphiphilic dicyanostilbene-functionalized thiophene(ACSTP)derivative was synthe-sized.Z-AcSTP was identified to dissolve in different organic solvents,accompanied with strong and tun-able fluorescence emission.However,when Z-AcSTP was dispersed in water,it was self-assembled into nanofibers,and the fluorescence was red shifted,accompanied with sharp decrease of intensity com-pared with that in DMSO.Furthermore,Z-form of ACSTP to its E-form under 365 nm irradiation led to the morphology transformation from nanofibers to nanosheets.Notably,upon addition of water-soluble pillar[5]arene(wP5),the nanofibers were transformed into fluorescent hollow particles due to the host-guest interactions between the pyridinium group and WP5 and the obtained fluorescent particles can be further applied in living cell imaging.

Easily Accessible and Highly Selective ＂Turn-on＂ Fluorescent Sensor for Imaging Cadmium in Living Cells

A new schiff base of phenothiazine derivative was designed for ratiometric sensing of Cd2＋ selectively. Upon the addition of Cd2＋ to the solution of phenothiazine derivative, the fluorescence intensity of it was enhanced in a linear fashion and the maximum fluorescence peak exhibited a blue shift from 575 nm to 525 nm. This ratiometric fluorescent sensor displays a very high sensitivity（detection limits were 0.34 and 1.0μmol/L of Cd2＋ using the visual fluorescence changes and UV-Vis changes, respectively）, a rapid response time（〈10 s） and high selectivity for Cd2＋ over other transition metal ions. Moreover, the living cells image experiments also demonstrate the value of the sen- sor in fluorescent visualization of Cd2＋ in the environmental and biological systems.