Search

Glioblastoma is the most fatal and insidious malignancy, due to the existence of the blood–brain barrier (BBB) and the high invasiveness of tumor cells. Abnormal mitochondrial viscosity has been identified as a key feature of malignancies. Therefore, this study reports on a novel fluorescent probe for mitochondrial viscosity, called ZVGQ, which is based on the twisted intramolecular charge transfer (TICT) effect. The probe uses 3-dicyanomethyl-1,5,5-trimethylcyclohexene as an electron donor moiety and molecular rotor, and triphenylphosphine (TPP) cation as an electron acceptor and mitochondrial targeting group. ZVGQ is highly selective, pH and time stable, and exhibits rapid viscosity responsiveness. In vitro experiments showed that ZVGQ could rapidly recognize to detect the changes in mitochondrial viscosity induced by nystatin and rotenone in U87MG cells and enable long-term imaging for up to 12 h in live U87MG cells. Additionally, in vitro 3D tumor spheres and in vivo orthotopic tumor-bearing models demonstrated that the probe ZVGQ exhibited exceptional tissue penetration depth and the ability to penetrate the BBB. The probe ZVGQ not only successfully visualizes abnormal mitochondrial viscosity changes, but also provides a practical and feasible tool for real-time imaging and clinical diagnosis of glioblastoma. [ABSTRACT FROM AUTHOR]

In this work, a fluorescent probe, TPABF-HS, was developed for detecting hydrogen sulfide (H2S) using a human serum albumin (HSA)-binding-based approach for amplifying the fluorescence signal and extending the linear correlation range. Compared to the most recent probes for H2S, the most interesting feature of the detection system developed herein was the especially wide linear range (0–1000 μM (0–100 eq.)), which covered the physiological and pathological levels of H2S. TPABF-HS could be used in applications high sensitivity and selectivity with an LOD value of 0.42 μM. Further, site-competition experiments and molecular docking simulation experiments indicated that signal amplification was realized by the binding of the TPABF fluorophore to the naproxen-binding site of HSA. Moreover, the extension of the measurement span could allow for applications in living cells and Caenorhabditis elegans for imaging both exogenous and endogenous H2S. This work brings new information to the strategy of signal processing by exploiting fluorescent probes. [ABSTRACT FROM AUTHOR]

Most of the ONOO− fluorescent probes have restricted applications because of their aggregation-caused quenching (ACQ) effect, long response time and low fluorescence enhancement. Herein, we developed a novel AIEgen fluorescent probe (PE-XY) based on a benzothiazole and quinolin scaffold with high sensitivity and selectivity for imaging of ONOO−. The results indicated that probe PE-XY exhibited fast response towards ONOO− with 2000-fold enhancement of fluorescence intensity ratio in vitro. Moreover, PE-XY exhibited a relatively high sensitivity (limit of detection: 8.58 nM), rapid response (<50 s), high fluorescence quantum yield (δ = 0.81) and excellent selectivity over other analytes towards ONOO−in vitro. Furthermore, PE-XY was successfully applied to detect endogenous ONOO− levels in living HeLa cells, C. elegans and inflammatory mice with low cytotoxicity. Overall, this work provided a novel fast-response and highly selective AIEgen fluorescent probe for real-time monitoring ONOO− fluctuations in living systems. [ABSTRACT FROM AUTHOR]

As essential biological thiols in organisms, Cys, Hcy, and GSH are closely related to each other, and they can be involved in various pathological processes if expression levels are abnormal. It is a challenge to develop effective fluorescence-based tools to selectively distinguish Cys from Hcy and GSH because of their common functional groups. For most existing Cys fluorescent probes, their application is greatly restricted by the influence of aggregation-caused quenching (ACQ). In this work, a novel fluorescent probe, PE-YW, for Cys was designed rationally via regulating its AIE-based effects. The probe PE-YW took advantage of a specific conjugate addition cyclization reaction between Cys and an acrylate moiety, inducing the aggregation of PE-OH and showing large turn-on fluorescence (about 7-fold). The probe could detect Cys over other amino acids with high selectivity and a low detection limit (LOD = 1.72 nM). In addition, PE-YW exhibited excellent performance, such as a high fluorescence quantum yield (δ = 0.8) and a fast response toward Cys (<20 min). Furthermore, PE-YW was used for fluorescence imaging in living HeLa cells and C. elegans. The results suggested that PE-YW was a suitable and potential fluorescence-based tool for detecting Cys in living systems. [ABSTRACT FROM AUTHOR]

Correction for 'A highly selective AIEgen fluorescent probe for visualizing Cys in living cells and C. elegans' by Ya-Xi Ye et al., New J. Chem., 2021, 45, 19073–19081. [ABSTRACT FROM AUTHOR]