A remarkable membrane-permeable fluorescent probe for real-time imaging of mitochondrial SO with high fidelity during ferroptosis.

Mitochondrial sulfur dioxide (SO) plays a double-edged role in cells, and the real-time and tracing of its dynamic behaviors to elucidate its complicated functions in detail is of great significance. Here, we developed a simple mitochondria-targeted fluorescent probe ZW for tracing SO with good membrane permeability. In probe ZW, the 1-phenylpyrrolidine-decorated benzopyrylium unit is employed as the selective response site for SO.

A single-molecule fluorescent probe for visualizing viscosity and hypoxia in lysosomes and zebrafish embryos.

Viscosity and hypoxia, as microenvironment parameters, play important roles in maintaining normal biological processes and homeostasis. Therefore, simultaneous and sensitive detection of these elements with simple and effective methods could offer precise information in biology. Here, we report a two-site lysosome-targeting fluorescent probe, NVP, for monitoring viscosity and nitroreductase with dual emission channels (emission shift is 86 nm).

Development of a polarity-sensitive ratiometric fluorescent probe based on the intramolecular reaction of spiro-oxazolidine and its applications for in situ visualizing the fluctuations of polarity during ER stress.

Polarity is a vital element in endoplasmic reticulum (ER) microenvironment, and its variation is closely related to many physiological and pathological activities of ER, so it is necessary to trace fluctuations of polarity in ER. However, most of fluorescent probes for detecting polarity dependent on the changes of single emission, which could be affected by many factors and cause false signals. Ratiometric fluorescent probe with "built-in calibration" can effectively avoid detection errors.

A pH-response-based fluorescent probe for detecting the mitophagy process by tracing changes in colocalization coefficients.

Mitochondria are not only the center of energy metabolism but also involved in regulating cellular activities. Quality and quantity control of mitochondria is therefore essential. Mitophagy is a lysosome-dependent process to clear dysfunctional mitochondria, and abnormal mitophagy can cause metabolic disorders.

Golgi apparatus-targeting fluorescent probe for the imaging of superoxide anion (O) in living cells during ferroptosis.

Ferroptosis is an emerging iron-dependent oxidative cell death type, and recently has been demonstrated to show close relation with Golgi apparatus (GA). Exploring the fluctuation of superoxide anion (O) level in GA during ferroptosis is of great significance to profoundly study the biological functions of GA in ferroptosis. Here, we present a GA-targeting probe (N-GA) to monitor cellular O during ferroptosis.

Single Fluorescent Probe for Multiple Tasks: Illuminating Lipid Droplets and Lysosomes in Dual Channels and Distinguishing Autophagy and Apoptosis.

Lipid droplets (LDs) and lysosomes play key roles in autophagy and cell apoptosis, and the discriminative visualization of the two organelles and simultaneously of autophagy and apoptosis is very helpful to understand their internal relationships. However, fluorescent probes that can concurrently achieve these tasks are not available currently. Herein, we delicately fabricate a robust probe CAQ2 for multiple tasks: illumination of LDs and lysosomes in dual emission colors as well as discriminative visualization of cell apoptosis and autophagy.

Construction of a polymer-based fluorescent probe with dual responsive sites for monitoring changes of lysosomal viscosity.

As highly dynamic organelles, lysosomes are involved in various physiological processes. The viscosity of lysosomes plays critical roles in maintaining their normal physiological function and abnormal variations of viscosity are associated with many diseases. Monitoring the changes of lysosomal viscosity could contribute to understanding lysosome-related physiological and pathological processes.

An FRET-based and ER-targeting fluorescent probe for tracking superoxide anion (O) in the hippocampus of the depressive mouse.

Exploration of the pathway for the excessive generation of O in hippocampus during depression is critical for the study on molecular mechanism of depression, and is currently still inconclusive. Herein, we put forward a hypothesis that depression increases the generation of O in hippocampus by triggering ER stress, and verified this hypothesis by constructing an FRET-based ER-targeting fluorescent probe (ER-CRh) which can provide ratiometric detection of O with high sensitivity and selectivity. The probe ER-CRh showed desirable ER-targeting capability, and could detect the endogenous O in the ER of the hippocampal neuronal cells experiencing ER stress.

A D-π-A-π-D type structure-based fluorescent probe for revealing the fluctuations of the ER polarity during ferroptosis.

Ferroptosis is a novel Fe(II)-mediated oxidative cell death form, and is closely related with endoplasmic reticulum (ER). Exploring the fluctuation of ER polarity during ferroptosis is highly important for the in-depth study of the biological roles of ER in ferroptosis. Herein, we present a ratiometric probe (BNS) for revealing the changes of the ER polarity in the living cells experiencing ferroptosis.

Development of a "double reaction" type-based fluorescent probe for the imaging of superoxide anion in living cells.

Superoxide anion (O) is an important ROS in living systems, and rapid and in situ detection of O is critical for the in-depth study of its roles in the closely related diseases. Herein, we present a "double reaction" type-based fluorescent probe (BZT) for the imaging of O in living cells. BZT employed a triflate group as a recognition site for O.

Development of a high polarity-sensitive fluorescent probe for visualizing the lipid droplets and endoplasmic reticulum with dual colors in living cells.

Lipid droplets (LDs) are unique organelles that control the lipid metabolism in cells. It has been identified that the generations of LDs derive from endoplasmic reticulum (ER) and they have closely related with amount of cellular activities for maintaining homeostasis. To further explore the detail interactions between LDs and ER, we have developed a novel polarity-sensitive fluorescent probe LP with distinct D-π-A-π-D framework and applied it to imaging LDs and ER with dual colors at the same time.

Chameleon-Like Fluorescent Probe for Monitoring Interplays between Three Organelles and Reporting Cell Damage Processes through Dramatic Color Change.

The in-depth study of the interplay and cooperation between multiple organelles is an important biological task. Single fluorescent probes for separate visualization of multiple organelles is a desirable molecular tool, but the construction of such a probe is extremely difficult owing to the lack of valid strategies. In this work, utilizing the reversible cyclization reaction and intermolecular π stacking mechanism, a robust fluorescent probe is constructed to discriminatively illuminate lipid droplets (LDs), mitochondria, and lysosomes with blue, green, and red emission colors, respectively.

Revealing the Phase Separation in ER Membranes of Living Cells and Tissues by NIR Ratiometric Imaging.

Biomembranes in the endoplasmic reticulum (ER) play indispensable roles in various bioactivities, and therefore, visualizing the phase separation in ER membranes is crucial for the studies on the fundamental biology of the ER. However, near-infrared (NIR) ratiometric imaging of the phase behaviors of the ER in living cells with different statuses and in diverse tissues has not been investigated. Herein, we developed a polarity-responsive NIR fluorescent probe () for the visualization of the phase behavior in ER membranes.

Development of an esterase fluorescent probe based on naphthalimide-benzothiazole conjugation and its applications for qualitative detection of esterase in orlistat-treated biosamples.

Esterase is a large hydrolysis family, and widely distributed in many kinds of cells. It is responsible for multiple physiological and pathological functions including metabolism, gene expression. While abnormality of esterase is associated with many pathological activities in obesity, Wolman's disease, and cancer.

Mitochondria-targeted and FRET-based fluorescent probe for the imaging of endogenous SO in living cells.

Sulfur dioxide (SO) is an important signal molecule in living systems, and plays a wide range of physiological functions. Real-time and in situ detection of the dynamic balance of SO in mitochondria is of great significance to in-depth study its biological roles. Herein, we have developed a mitochondria-targeted fluorescent probe Nap-L based on the FRET mechanism to detect SO in living cells.

The development of a biotin-guided and mitochondria-targeting fluorescent probe for detecting SO precisely in cancer cells.

Mitochondrial sulfur dioxide (SO) is very closely associated with various activities of cancer cell. However, the specific physiological and pathological roles of mitochondrial SO in cancer cells are still not well defined. Lacking a powerful molecular tool for detecting mitochondrial SO in cancer cells precisely is an essential factor.

Noninvasive Cancer Diagnosis Based on a Viscosity-Activated Near-Infrared Fluorescent Probe.

Effective and cancer diagnosis is expected to ease the burden of continued increased deaths worldwide. Herein, we proposed viscosity of the tumor microenvironment as a biomarker and further develop a versatile optical agent, for monitoring tumor microenvironmental viscosity alterations to achieve cancer diagnosis, therapeutic effect tracking, and anticancer drug screening. When in highly viscous media, near-infrared signals of are specifically activated, endowing the probe with the capacity of avoiding biological autofluorescence and achieving high signal-to-noise ratio imaging.

An endoplasmic reticulum targetable turn-on fluorescence probe for imaging application of carbon monoxide in living cells.

Carbon monoxide (CO) is a significant mediator in regulating endoplasmic reticulum (ER) stress, and its level may play a potential role in the treatment of vascular diseases combined with ER stress. In-situ visualization of CO in the ER helps to elucidate its physiological and pathological mechanistic behavior. Herein, a novel CO fluorescent probe (Na-CM-ER) with ER-targeting characteristics was structured.

A dual-site controlled fluorescent sensor for the facile and fast detection of HO in DO by two turn-on emission signals.

Currently, fluorescent sensors for the detection of HO in DO are still quite rare. Herein, we present a dual-site controlled fluorescent sensor (CF-DO) for the detection of HO in DO. As the HO content in DO decreases (namely, the purity of DO increases), sensor CF-DO provides two turn-on fluorescence signals.

An Ultrasensitivity Fluorescent Probe Based on the ICT-FRET Dual Mechanisms for Imaging β-Galactosidase in Vitro and ex Vivo.

Emergence of fluorescence imaging with real-time and manners has revolutionized the fields of tracing and defining enzymes in biological systems. β-galactosidase is a kind of enzyme that plays vital roles in controlling multitudes of cellular functions and participating in disease pathogenesis. Thus, building fluorescent probes with high sensitivity and fidelity for visualizing β-galactosidase in biological systems is very significative.

An ultrasensitive ratiometric fluorescent probe based on the ICT-PET-FRET mechanism for the quantitative measurement of pH values in the endoplasmic reticulum (ER).

Herein, we present a dual-site ratiometric fluorescent probe based on the ICT-PET-FRET mechanism for the detection of pH in the ER. The probe showed a highly sensitive response to pH in the range of 5.0-7.

Förster Resonance Energy Transfer-Based Fluorescent Probe for the Selective Imaging of Hydroxylamine in Living Cells.

Hydroxylamine (HA) is an important product of cell metabolism and plays a significant role in many biological processes, and therefore, real-time imaging of HA is of great importance for the in-depth study of its physiological and pathological functions. However, a HA-specific fluorescent probe is currently lacking primarily because the highly selective HA-responsive site is undeveloped. To address this critical issue, we present a HA-specific FRET-based fluorescent probe () for the selective detection of HA in living systems.