A near-infrared fluorescent molecular rotor for viscosity detection in biosystem and fluid beverages.

Viscosity is closely associated with physiological and pathological processes, as well as food quality. Herein, a novel fluorescent molecular rotor, BMCY-V, was presented and applied for detection of viscosity. BMCY-V contained a benzoindole unit as electron donor and a malononitrile group as acceptor.

Ingenious fluorescent probes for biogenic amine and their applications in bioimaging and food spoilage detection.

Food safety issues have received much attention. Biogenic amines are considered important markers of food spoilage. Accurate detection of biogenic amines is important for food quality monitoring.

Achieving long-lived white circularly polarized luminescence from carbonized polymer dots phosphorescence resonance energy transfer.

Achieving white-light emission, especially long-lived white circularly polarized luminescence, is challenging. Herein, chiral phosphorescent carbonized polymer dots (CPDs) have been prepared by using chiral polymer sodium alginate and chiral small molecule L-lysine as precursors. Benefiting from the efficient triplet-to-singlet phosphorescence resonance energy transfer (PRET), CPD-based long-lived warm white CPL has been achieved for the first time.

Dissecting lysosomal viscosity fluctuations in live cells and liver tissues with an ingenious NIR fluorescent probe.

Viscosity is a pivotal component in the cell microenvironment, while lysosomal viscosity fluctuation is associated with various human diseases, such as tumors and liver diseases. Herein, a near-infrared fluorescent probe (BIMM) based on merocyanine dyes was designed and synthesized for detecting lysosomal viscosity in live cells and liver tissue. The increase in viscosity restricts the free rotation of single bonds, leading to enhanced fluorescence intensity.

Chiral Phosphorescent Carbonized Polymer Dots Relayed Light-Harvesting System for Color-Tunable Circularly Polarized Room Temperature Phosphorescence.

Carbonized polymer dots (CPDs) with a circularly polarized fluorescence property have received increasing attention in recent years. However, it is still a great challenge to construct circularly polarized room-temperature phosphorescence (CPRTP) CPDs. Herein, a simple approach to the synthesis of intrinsically CPRTP CPDs for the first time by utilizing sodium alginate and l-/d-arginine as precursors under relatively mild reaction conditions is presented.

Small-molecule fluorescent probes for bioactive species in inflammatory disease: arthritis, pneumonia and hepatitis.

Inflammation as an adaptive response underlies a wide variety of physiological and pathological processes. The progression of inflammation is closely intertwined with various bioactive molecules. To dissect the biological mechanisms and physiopathological functions of these molecules, exploitation of versatile detection mean is of great importance.

Theoretical characterization of two-photon fluorescent probes for nitric oxide detection: sensing mechanism, photophysical properties and protonation effects.

Nitric oxide (NO) is an important signal molecule in biological systems and is correlated with many physiological processes and pathological diseases. To date, numerous fluorescent probes based on -diamino aromatics have been designed and synthesized for NO detection utilizing the principle of photoinduced electron transfer (PET). However, the underlying PET mechanism has rarely been validated, and a systematic computational study on the photophysical properties is urgently desired.

Small Molecular Fluorescent Probes for Alzheimer's Disease Associated Active Species.

Alzheimer's disease (AD) is a progressive neurodegenerative disorder and is the main cause of dementia worldwide. As the pathogenesis of AD is quite complicated, there is continuous attention to AD-associated active species, such as amyloid-β plaques, neurofibrillary tangles, metal ions, reactive oxygen/nitrogen/sulphur species, cholinesterase, viscosity, formaldehyde and so on. To this end, a series of small molecular fluorescent probes for these active species have been explored for early diagnosis and even remedy of AD.

An ESIPT-based ratiometric fluorescent probe for detecting HO in water environment and biosystems.

The outbreak of the COVID-19 has resulted in a great increase in the use of HO disinfectant, which is listed as one of the commonly used disinfectants for COVID-19 by the U.S. Environmental Protection Agency.

Recent Progress of Small-Molecule Ratiometric Fluorescent Probes for Peroxynitrite in Biological Systems.

Peroxynitrite (ONOO ) as a major reactive oxygen species plays important roles in cellular signal transduction and homeostatic regulation. Precise detection of ONOO in biological systems is vital for exploring its physiological and pathological function. Among numerous detection methods, fluorescence imaging technology using fluorescent probes offers some advantages, including simple operation, high sensitivity and selectivity, as well as real-time and nondestructive detection.

Recent progress in small-molecule fluorescent probes for endoplasmic reticulum imaging in biological systems.

Endoplasmic reticulum (ER) is an indispensable organelle in eukaryotic cells involved in protein synthesis and processing, as well as calcium storage and release. Therefore, maintaining the quality of ER is of great importance for cellular homeostasis. Aberrant fluctuations of bioactive species in the ER will result in homeostasis disequilibrium and further cause ER stress, which has evolved to contribute to the pathogenesis of various diseases.

New β-diketone-boron difluoride based near-infrared fluorescent probes for polarity detection.

Two new β-diketone-boron difluoride based near-infrared fluorescent probes 1 and 2 which exhibit polarity sensitivity have been designed and synthesized. Probes 1 and 2 are composed of a β-diketone-boron difluoride moiety as an acceptor unit, and a diethylamino group and a phenolic hydroxyl group as donor units. The long conjugate structures form a "donor-acceptor-donor" configuration, induce intramolecular charge transfer (ICT), and confer near-infrared fluorescence emission and excellent polarity sensitivity.

A new fluorescent probe for neutral to alkaline pH and imaging application in live cells.

A new pH-sensitive fluorescent probe NAP-MDA was designed and synthesized. NAP-MDA consists of 1,8-naphthalimide as fluorophore, morpholine and N,N-dimethylethylenediamine as pH-responsive groups. Due to the photoinduced electron transfer (PET) mechanism, the fluorescence of 1, 8-naphthalimide was thoroughly quenched under alkaline condition (pH > 10.

Small Molecular Fluorescent Probes for Imaging of Viscosity in Living Biosystems.

Viscosity, as a vital microenvironment parameter, is tightly associated with multitudinous cellular processes and diseases. Recently, precise visualization of viscosity has started to arouse more and more interest. However, owing to the complicated character, it is still a huge challenge to directly observe viscosity in living systems.

The photophysical properties and imaging application of a new polarity-sensitive fluorescent probe.

A new excited-state intramolecular proton transfer (ESIPT) based and polarity-sensitive fluorescent probe M-HA was easily developed by conjugated connection of indole and 2'-hydroxyacetophenone through (E)-2-chloro-3-(hydroxymethylene)cyclohex-1-enecarbaldehyde. M-HA shows near-infrared fluorescence, high molar absorption coefficient and a large Stokes shift in various common solvents. In particular, M-HA exhibits red-shifted maximum emission wavelength, and extraordinarily high fluorescence intensity and quantum yield in high-polarity solvents.

Two-photon fluorescence visualization of lysosomal pH changes during mitophagy and cell apoptosis.

We herein develop a novel two-photon fluorescent probe termed L-pH for visualization of lysosomal pH within live cells. L-pH is composed of three moieties, including naphthalimide fluorophore as a fluorescence off-on response moiety, piperazine and morpholine groups as lysosomal targeting and pH responsive sites, as well as a reactive benzyl chloride segment for further lysosomal anchoring. The experimental results demonstrate that L-pH can instantaneously respond to various pH values with high sensitivity and selectivity, and has low cytotoxicity and excellent photostability.

Versatile Fluorescent Probes for Imaging the Superoxide Anion in Living Cells and In Vivo.

The superoxide anion (O ) is widely engaged in the regulation of cell functions and is thereby intimately associated with the onset and progression of many diseases. To ascertain the pathological roles of O in related diseases, developing effective methods for monitoring O in biological systems is essential. Fluorescence imaging is a powerful tool for monitoring bioactive molecules in cells and in vivo owing to its high sensitivity and high temporal-spatial resolution.

Monitoring mitochondrial pH with a hemicyanine-based ratiometric fluorescent probe.

Mitochondria as essential organelles play critical roles in cellular metabolism. Mitochondrial pH is a vital parameter that directly affects the unique function of mitochondria. Herein, we present a new ratiometric fluorescent probe M-pH for monitoring the pH within the mitochondria.

Two-photon imaging of the endoplasmic reticulum thiol flux in the brains of mice with depression phenotypes.

Depression is a common mental illness with high morbidity and mortality. Mounting evidence suggests that an imbalance of the oxidant-antioxidant defence system is strongly correlated with depression and the dysfunction of the endoplasmic reticulum (ER) is strongly related to the oxidative stress. Therefore, as vital and abundant antioxidants in the ER, biothiols may contribute to the etiology of depression.

Simultaneous Fluorescence Visualization of Endoplasmic Reticulum Superoxide Anion and Polarity in Myocardial Cells and Tissue.

Diabetic cardiomyopathy (DCM) is a critical complication of diabetes, the accurate pathogenesis of which remains elusive. It is widely accepted that endoplasmic reticulum (ER) stress and abnormal fluctuations of reactive oxygen species (ROS) are considered to be closely associated with progress of DCM. In addition, DCM-induced changes of myocardial tissue and ROS-derived oxidation of proteins will cause changes of the hydrophilic and hydrophobic domains and may further seriously alter the myocardial cell polarity.

Ratiometric photoacoustic imaging of endoplasmic reticulum polarity in injured liver tissues of diabetic mice.

As one of the complications of diabetes, liver injury results in significant hazards. Therefore, accurately diagnosing diabetes-induced liver injury beforehand is crucial for the warning and treatment of hepatic diseases. Diabetes-induced liver injury can cause changes in the microstructure and morphology of liver tissue, leading to changes in the hydrophilic and hydrophobic domains in the endoplasmic reticulum (ER), which is closely associated with changes in cellular ER polarity.

Enhanced expression of caveolin-1 possesses diagnostic and prognostic value and promotes cell migration, invasion and sunitinib resistance in the clear cell renal cell carcinoma.

Caveolin-1 (CAV1) has been identified to be up-regulated in many cancers, including clear cell renal cell carcinoma (ccRCC). However, its potential function is still unclear in ccRCC. In this study, we demonstrated that CAV1 was frequently overexpressed in renal cell carcinoma tissues and cells, and was significantly associated with various clinicopathological parameters.