A two-in-one probe: imaging lipid droplets and endoplasmic reticulum in tandem.

The endoplasmic reticulum (ER) and lipid droplets (LDs) intricately interact in cellular processes, with the ER serving as a hub for lipid synthesis and LDs acting as storage organelles for lipids. Developing fluorescent probes that can simultaneously visualise the ER and LDs provides a means for real-time and specific visualisation of these subcellular organelles and elucidating their interaction. Herein, we present synthetically simple and novel donor-π-acceptor styryl fluorophores (PFC, PFN and PFB) incorporating pentafluorophenyl (PFP) to demonstrate exquisite discriminative imaging of ER and LD with a single excitation wavelength.

Large Room-Temperature Magnetoresistance in a High-Spin Donor-Acceptor Conjugated Polymer.

Open-shell conjugated polymers (CPs) offer new opportunities for the development of emerging technologies that utilize the spin degree of freedom. Their light-element composition, weak spin-orbit coupling, synthetic modularity, high chemical stability, and solution-processability offer attributes that are unavailable from other semiconducting materials. However, developing an understanding of how electronic structure correlates with emerging transport phenomena remains central to their application.

Lipid Droplets Specific Fluorophore for Demarcation of Normal and Diseased Tissues.

Using high-fidelity, permeable, lipophilic, and bright fluorophores for imaging lipid droplets (LDs) in tissues holds immense potential in diagnosing conditions such as diabetic or alcoholic fatty liver disease. In this work, we utilized linear and Λ-shaped polarity-sensitive fluorescent probes for imaging LDs in both cellular and tissue environments, specifically in rats with diabetic and alcoholic fatty liver disease. The fluorescent probes possess several key characteristics, including high permeability, lipophilicity, and brightness, which make them well-suited for efficient LD imaging.

Ultrasensitive Room Temperature Infrared Photodetection Using a Narrow Bandgap Conjugated Polymer.

Photodetectors operating across the short-, mid-, and long-wave infrared (SWIR-LWIR, λ = 1-14 µm) underpin modern science, technology, and society in profound ways. Narrow bandgap semiconductors that form the basis for these devices require complex manufacturing, high costs, cooling, and lack compatibility with silicon electronics, attributes that remain prohibitive for their widespread usage and the development of emerging technologies. Here, a photoconductive detector, fabricated using a solution-processed narrow bandgap conjugated polymer is demonstrated that enables charge carrier generation in the infrared and ultrasensitive SWIR-LWIR photodetection at room temperature.

Improved lipophilic probe for visualizing lipid droplets in erastin-induced ferroptosis.

Studying the viscosity of lipid droplets (LDs) provides insights into various diseases associated with LD viscosity. Ferroptosis is one such process in which LD viscosity increases due to the abnormal accumulation of lipid ROS (reactive oxygen species) caused by peroxidation. For investigating the LD imaging and ferroptosis, we developed two molecules (NNS and DNS) that show significant Stokes shifts (182-232 nm) and utilized them for sub-cellular imaging.

Fluorescent styryl pyridine--oxide probes for imaging lipid droplets.

Lipid droplets (LDs) have emerged as major regulators of cellular metabolism, encompassing lipid storage, membrane synthesis, viral replication, and protein degradation. Exclusive studies have suggested a direct link between LDs and cancer, as a notable abundance of LDs is found in cancerous cells. Therefore, monitoring the location, distribution, and movements of LDs is of paramount importance for understanding their involvement in biological processes.

Styryl-NIR Mitochondrial Probes with Rapid HOCl Detection in Live-Cells.

Hypochlorous acid (HOCl) is critical for maintaining immune system balance, but it can harm mitochondria by hindering enzyme activity, leading to decreased ATP and increased cell death. In this study, we have designed a fluorophore with a pyridinium scaffold for selective staining of the mitochondria and to detect hypochlorite. The fluorophore exhibits strong solvatochromic emission due to intramolecular charge transfer and excellent sub-cellular localization in the mitochondria.

α-Cyanostilbene: a multifunctional spectral engineering motif.

Aggregation-induced emission (AIE) is a unique photophysical phenomenon of organic chromophores, exhibiting a significant emission enhancement in the condensed phase (aggregate/solid/film) than in the solution phase. This remarkable feature offers excellent strategies to obtain molecular materials possessing unique spectral signatures such as high fluorescence intensity, excellent quantum yield, large Stokes shift, and exquisite optoelectronic properties. Unlike a great library of articles with propeller-shaped tetraphenylethene molecular frameworks, reviews based on the mechanistic understandings of α-cyanostilbenes are relatively rare.

Magnetic Ordering in a High-Spin Donor-Acceptor Conjugated Polymer.

The development of open-shell organic molecules that magnetically order at room temperature,which can be practically applied, remains a grand challenge in chemistry, physics, and materials science. Despite the exploration of vast chemical space, design paradigms for organic paramagnetic centers generally result in unpaired electron spins that are unstable or isotropic. Here, a high-spin conjugated polymer is demonstrated, which is composed of alternating cyclopentadithiophene and benzo[1,2-c;4,5-c']bis[1,2,5]thiadiazole heterocycles, in which macromolecular structure and topology coalesce to promote the spin center generation and intermolecular exchange coupling.

Emission and Color Tuning of Cyanostilbenes and White Light Emission.

White-light-emitting diodes are energy efficiency replacement of conventional lighting sources. Herein, we report the luminescent behavior of three simple cyanostilbenes with triphenylamine-donating groups bearing different electron-withdrawing groups (phenyl, pyridyl, and -nitrophenyl) in a common donor (D)-π-acceptor (A) α-cyanostilbene construct along with their thermal and electrochemical properties. The density functional theory (DFT) studies reveal that aggregation-induced emission characteristic feature of the D-π-A dyes is inversely proportional to the intramolecular charge transfer (ICT) effect, that is, phenyl-and pyridyl-substituted compounds show characteristic aggregation-induced emission in water, whereas the ICT effect is dominant for the nitro derivative.

Phenothiazine Functionalized Multifunctional A-π-D-π-D-π-A-Type Hole-Transporting Materials via Sequential C-H Arylation Approach for Efficient and Stable Perovskite Solar Cells.

Three phenothiazine-based A-π-D-π-D-π-A-type small molecules containing various terminal acceptor units, which act as Lewis base blocks, have been synthesized via an efficient and step-economical, direct C-H arylation strategy in the aim toward the development of hole-transporting materials (HTMs) with multifunctional features (such as efficient hole extraction layer, trap passivation layer, and hydrophobic protective layer) for perovskite solar cells (PrSCs). Optical-electrochemical correlation and density functional theory studies reveal that dicyanovinylene acceptor in SGT-421 downshifted the highest occupied molecular orbital (HOMO) level (-5.41 eV), which is more proximal to the valence band (-5.

Tuning of optical properties of p-phenyl ethenyl-E-furans: A Solvatochromism and Density functional theory.

p-Phenyl ethenyl-E-furans (1-6) with varied electron donor and acceptor substituent (NO, CN, Cl, H, OCH, NH) were synthesized and studied the substituent induced optical properties (dipole moment, transition dipole moment, oscillator strength, optical band gap, hyperpolarizability) using Solvatochromism and Density functional theory. It is shown that furan acts as a weak electron donor in presence of an electron withdrawing p‑phenyl substituent (NO, CN, Cl), whereas furan acts as a weak electron acceptor in presence of an electron donating p‑phenyl substituent (OCH, NH). In comparison to ethenylfuran 4, the HOMO-LUMO energy band gap is decreased upon increasing the electron donating or electron withdrawing nature of the phenyl ring.

Substituent Dependent Optical Properties of p-phenyl Substituted ethenyl-E-thiophenes.

Various electron donor and acceptor substituted (NO, CN, Cl, H, OCH, NH) p-phenyl ethenyl-E- thiophenes (1-6) were synthesized and substituent dependent optical properties (dipole moment, transition dipole moment, oscillator strength, optical band gap, hyperpolarizability) were studied using Solvatochromism and Density functional theory. It is shown that thiophene acts as a weak electron donor in presence of an electron withdrawing p-phenyl substituent (NO, CN, Cl), whereas thiophene acts as a weak electron acceptor in presence of an electron donating p-phenyl substituent (OCH, NH). In comparison to ethenyl thiophene 4, the HOMO-LUMO energy band gap is decreased upon increasing the electron donating or electron withdrawing capacity of p-phenyl substituent.

The impact of heteroatom substitution on cross-conjugation and its effect on the photovoltaic performance of DSSCs - a computational investigation of linear vs. cross-conjugated anchoring units.

The unusual bonding pattern and proximal heteroatom substitution in π-cross conjugation produced distinct changes in the energy levels and photophysical behaviour of the dyes. To seek an understanding of the origin of these fluctuations, we have carried out a detailed computational investigation on a series of D-π1-π2 (A1)-A2 structured dyes comprised of common donor-spacer (auxiliary acceptor) units but varied the anchoring parts. In this study, we introduced a novel dimethylamino substituted fluorene-based triarylamine donor unit and evaluated its donating strength.

Direct observation of the rise of delayed fluorescence in dithienylbenzothiadiazole and its role in the excited state dynamics of a donor-acceptor-donor molecule.

Dithienylbenzothiadiazole (DTBT) is used as a building block in several molecules having application in organic light emitting devices (OLED) and organic photovoltaic (OPV) devices. Delayed fluorescence (DF) is the preferred design principle employed currently in OLED research. DTBT has excellent delayed fluorescence properties which makes this moiety a potentially viable OLED material.

Photoisomerization of Trans Ortho-, Meta-, Para-Nitro Diarylbutadienes: A Case of Regioselectivity.

A series of ortho-, meta- and para-substituted trans-nitro aryl (phenyl and pyridyl) butadienes have been synthesized and characterized. The effect of substitution and positional selectivity on their fluorescence and photoisomerization were systematically investigated. Among all dienes, meta- and para-nitro phenyl-substituted derivatives exhibit remarkable solvatochromic emission shifts due to intramolecular charge transfer.