Exploring -Six-Membered--Heterocycle BODIPY Rotors as AIE Probes for Fluorescence Imaging Subcellular Viscosity in Organelles.

Aggregation-induced emission (AIE)-type small-molecular fluorescent rotors have attracted wide interest due to their inherent excellent properties in bioimaging viscosity, which can potentially reveal the relationships between microviscosity and related diseases. Although many fluorescent probes have been designed, easy-to-prepare and multifunctional AIE rotors remain a hot topic and less reported. Herein, four easy-to-prepare and water-soluble -pyrimidine/pyridine BODIPY-based multifunctional fluorescent probes were rationally designed to investigate the effects of the number and position of nitrogen in six-membered--heterocycles on viscosity, AIE, and viscosity imaging.

Methyl-free meso-thiazole-substituted red-shifted BODIPY-based molecular rotor for fluorescence imaging viscosity in mitochondria.

Molecular fluorescent rotors based on boron dipyrromethenes (BODIPYs) were intensively explored for monitoring the environmental viscosity variations, due to its critical functions in many associated diseases. Although various strategies have been used, red-shifted BODIPY-based fluorescent rotors with large Stokes shifts through one-step reaction remain a challenging topic due to the tedious synthetic procedures. In this manuscript, for the first time, through one-step reaction, 1,7-dimethyl-free meso-thiazole/benzothiazole BODIPYs were used to construct red-shifted fluorescent rotors with large Stokes shifts, which could be used for monitoring cellular viscosity changes with mitochondrial localization.

Mitochondria-targeting probes with large Stokes shift for detecting Amyloid-β and cellular viscosity changes.

For effective in vivo applications, imaging probes must exhibit sufficient tissue penetration depth, high sensitivity, and specificity. Increasing evidence suggests that pathological accumulation of Aβ results in elevated mitochondrial viscosity. To achieve red-shifted absorption and emission characteristics of small-molecule theranostic agents and to enhance their mitochondrial targeting efficiency, a series of M-series probes (M13 ∼ M15) was rationally designed based on the previously reported Q-series compounds.

A lysosome-targetable multifunctional fluorescent probe based on intramolecular NHNH hydrogen bonding for detection of hypochlorite and cyanides.

The creation of a singular fluorescent probe for the detection of various analytes is crucial for comprehending the interactions among analytes in living cells. This study presents a novel multifunctional fluorescent probe, designated Lyso-Nap-Py, which utilizes distinctive intramolecular NHNH hydrogen bonding for the simultaneous detection of hypochlorite and cyanides within living cells. This probe demonstrates the ability to detect cyanides and hypochlorite, offering advantages including high selectivity, fluorescence turn-off at 638 nm, a low limit of detection, and rapid response times.

Novel förster resonance energy transfer (FRET)-based ratiometric fluorescent probe for detection of cyanides by nucleophilic substitution of aromatic hydrogen (SNArH).

The development of novel fluorescent probes for real-time detection of cyanides (CN) in environmental and biological systems has become a significant focus in chemical sensing. Particularly, ratiometric fluorescence sensing offers a unique method for precise and quantitative detection of cyanides, even under complex conditions. We report herein the design of a new ratiometric fluorescent probe for cyanides based on modulation of Förster resonance energy transfer (FRET) coupled with novel cyanide-induced nucleophilic substitution of aromatic hydrogen (SNArH).

Modulation of intramolecular freedom for tuning fluorescence imaging and photooxidation of amyloid-β aggregates.

Alzheimer's disease (AD) is distinguished by amyloid-β (Aβ) deposition and plaque formation, prompting significant interest in fluorescence imaging and photooxidation of Aβ aggregates for diagnostic and intervention purposes. However, the molecular engineering required to modulate fluorescence imaging and photooxidation of Aβ presents notable challenges. Here, we present the design of four small molecules (BTD-SZ, BTD-YD, BTD-TA-SZ, and BTD-TA-YD) aimed at investigating the influence of intramolecular freedom of movement on imaging and photooxidation.

Rational construction and evaluation of a dual-functional near-infrared fluorescent probe for the imaging of Amyloid-β and mitochondrial viscosity.

Alzheimer's disease is a fatal, incurable, chronic neurodegenerative disease. Diagnosis in its early and even preclinical stages will be beneficial for its prevention and treatment. In the accepted pathological theory, abnormal accumulation of Aβ protein and abnormal mitochondrial function, including changes in mitochondrial viscosity, is closely related to Alzheimer's disease.

Enhanced β-Amyloid Aggregation in Living Cells Imaged with Quinolinium-Based Spontaneous Blinking Fluorophores.

Abnormal accumulation of intracellular and extracellular β-amyloid (Aβ) aggregates is closely related to the pathogenesis of Alzheimer's disease (AD). In this work, we use quinolinium derivatives with electron-rich aniline substituents as the skeletons to develop a set of spontaneous blinking fluorophores by the formation of long-lived radicals. These probes can target Aβ aggregates and exhibit strong deep-red emission upon binding to Aβ aggregates.