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Conjugated oligoelectrolytes (COEs) comprise a class of cell‐membrane intercalating molecules that serve as effective optical reporters. However, little is known about the photophysical properties of COEs in biological environments such as buffers, cell membranes, and intracellular organelles, which is critical to optimize performance. Herein, how COE self‐assembly depends on the dielectric environment (polarity and ion content) is explored based on the representative molecule 6‐ring phenylenevinylene (PV) conjugated oligoelectrolyte (COE‐S6), and its optical properties within mammalian cells are subsequently studied. Two‐photon fluorescence lifetime imaging microscopy (FLIM), confocal laser scanning microscopy, and optical properties in solutions are brought together to obtain information about the location, accumulation, and characteristics of the local surroundings. FLIM imaging lifetime phasor plots, decays, and fluorescence spectra on stained mammalian cells provide evidence of successful COE‐S6 internalization via endocytosis. The fluorescence lifetime of COE‐S6 is identical when in A549 mammalian cells and in giant unilamellar vesicle model membranes, thereby providing a correlation between living system and artificial constructs. [ABSTRACT FROM AUTHOR]

Understanding the genetic causes of evolutionary diversification is challenging because differences across species are complex, often involving many genes. However, cases where single or few genetic loci affect a trait that varies dramatically across a radiation of species provide tractable opportunities to understand the genetics of diversification. Here, we begin to explore how diversification of bioluminescent signals across species of cypridinid ostracods ("sea fireflies") was influenced by evolution of a single gene, cypridinid‐luciferase. In addition to emission spectra ("colour") of bioluminescence from 21 cypridinid species, we report 13 new c‐luciferase genes from de novo transcriptomes, including in vitro assays to confirm function of four of those genes. Our comparative analyses suggest some amino acid sites in c‐luciferase evolved under episodic diversifying selection and may be associated with changes in both enzyme kinetics and colour, two enzymatic functions that directly impact the phenotype of bioluminescent signals. The analyses also suggest multiple other amino acid positions in c‐luciferase evolved neutrally or under purifying selection, and may have impacted the variation of colour of bioluminescent signals across genera. Previous mutagenesis studies at candidate sites show epistatic interactions, which could constrain the evolution of c‐luciferase function. This work provides important steps toward understanding the genetic basis of diversification of behavioural signals across multiple species, suggesting different evolutionary processes act at different times during a radiation of species. These results set the stage for additional mutagenesis studies that could explicitly link selection, drift, and constraint to the evolution of phenotypic diversification. see also the Perspective by Danielle M. DeLeo and Heather D. Bracken#x02010;Grissom. [ABSTRACT FROM AUTHOR]

The synthesis of a new conjugated oligoelectrolyte (COE), namely DSAzB, is described, which contains a conjugated core bearing a diazene moiety in the center of its electronically delocalized structure. Similar to structurally related phenylenevinylene‐based COEs, DSAzB readily intercalates into model and natural lipid bilayer membranes. Photoinduced isomerization transforms the linear trans COE into a bent or C‐shape form. It is thereby possible to introduce DSAzB into the bilayer of a cell and disrupt its integrity by irradiation with light. This leads to controlled permeabilization of membranes, as demonstrated by the release of calcein from DMPG/DMPC vesicles and by propidium iodide influx experiments on S. epidermidis. Both experiments support that the permeabilization is selective for the light stimulus, highly efficient, and repeatable. Target‐selective and photoinduced actions demonstrated by DSAzB may have broad applications in biocatalysis and related biotechnologies. [ABSTRACT FROM AUTHOR]

A membrane-intercalating conjugated oligoelectrolyte (COE), PTTP, was designed and synthesized with the goal of providing red-shifted absorption spectra relative to previously synthesized COE analogs. Specifically, electron-rich and electron-poor subunits were introduced in the conjugated backbone to modulate the band gap. PTTP exhibits maxima of absorption at 507 nm and of emission at 725 nm. PTTP can also efficiently function to generate singlet oxygen in situ (ΦΔ≈20 %) and has appropriate topology and dimensions to interact with lipid membranes. The resulting rapid membrane insertion and sensitizing ability provide PTTP with a highly efficient antibacterial capability under a low light dose (0.6 J cm−2) toward Gram-negative bacteria E. coli, making it a remarkably efficient optically mediated antimicrobial agent. [ABSTRACT FROM AUTHOR]

A mechanistic study of the DNA interfacial layer that enhances the photoresponse in n-type field-effect transistors (FET) and lateral photoconductors using a solution-processed fullerene derivative embedded with disperse-red dye, namely PCBDR, is reported. Incorporation of the thin DNA layer simultaneously leads to increasing the electron injection from non-Ohmic contacts into the PCBDR active layer in dark and to increasing the photocurrent under irradiation. Such features lead to the observation of the enhancement of the photoresponsivity in PCBDR FETs up to 103. Kelvin probe microscopy displays that in the presence of the DNA layer, the surface potential of PCBDR has a greater change in response to irradiation, which is rationalized by a larger number of photoinduced surface carriers. Transient absorption spectroscopy confirms that the increase in photoinduced carriers in PCBDR under irradiation is primarily ascribed to the increase in exciton dissociation rates through the PCBDR/DNA interface and this process can be assisted by the interfacial dipole interaction. [ABSTRACT FROM AUTHOR]

Samples of Ba2.97-xEu0.03TbxMg1-xLixSi2O8 are prepared by microwave-assisted sol--gel reactions of BaCO3, Mg(NO3)2, (Et-O)4Si, Tb(NO3)3, Eu(NO3)3, MnCO3, and Li2CO3 dissolved in a mixture of EtOH, H2O, AcOH, and citric acid (heating the obtained powder to 400 °C for 4 h and to 650 °C for 6 h). Microwave heating leads to materials with very high phase purity not obtainable using furnace-based preparation methods. Ba2.64Eu0.06Tb0.3Mg0.68Mn0.02Li0.3Si2O8 exhibits red, green, and blue emission due to the dopant ions Eu2+, Tb3+, and Mn2+. The light produced is a cool white light with warmer colors limited by the solubility limit of Tb3+ in Ba3MgSi2O8. [ABSTRACT FROM AUTHOR]

The title compound is prepared by a rapid and energy efficient microwave assisted solid state reaction of stoichiometric amounts of CaCO3, MgO, SiO2, and Eu2O3 using small amounts of H3BO3 as flux (domestic microwave oven). [ABSTRACT FROM AUTHOR]