Probe For Detection Of Hypochlorous Acid Research Articles

Sensing mechanism of the benzo-bodipy based fluorescent probe for Hypochlorous acid detection: Invalidity of photoinduced electron transfer

In vivo real-time detection of hypochlorous acid (HClO) in biological systems plays a crucial role in diagnosing immune-related diseases. Experimentally, a benzo-bodipy probe based on the photo-induced electron transfer (PeT) sensing mechanism has been developed for live fluorescence imaging. However, there have been no theoretical studies conducted to substantiate the precision of the sensing mechanism. This paper employs density functional theory (DFT) and time-dependent density functional theory (TDDFT) methods to investigate the fluorescence detection mechanism of benzo-bodipy derivatives (BBy-T and BBy-TO), proposing a detection approach based on dark nπ* state quenching. The study reveals that the fluorescence quenching mechanism of BBy-T is primarily regulated by a thiomorpholine moiety, involving a dark nπ* state transition non-radiatively. Furthermore, this paper explains the fluorescence enhancement observed in BBy-TO. Theoretical investigations demonstrate, based on frontier molecular orbitals (FMOs) and hole-electron analysis, that the fluorescence enhancement for BBy-TO is not governed by the previously proposed intramolecular charge transfer (ICT) mechanism in experiments but rather follows a locally excited (LE) ππ* pattern. This work offers new insights for the design of novel fluorescence probes based on bodipy and benzo derivatives, expanding the understanding of their fluorescence properties.

A stable ratiometric fluorescent probe for hypochlorous acid detection and rheumatoid arthritis evaluation.

A ratiometric fluorescent probe (MeO-CNPPV Pdots) based on the principle of fluorescence resonance energy transfer (FRET) was designed for hypochlorous acid (HOCl) and rheumatoid arthritis (RA) detection. The presence of HOCl can block the energy transfer from CNPPV to MeOTPATBT, resulting in a ratio change in the fluorescence of Pdots (I600 nm/I680 nm). This strategy provides a valuable paradigm in early RA evaluation.

Development of a new water-soluble fluorescence probe for hypochlorous acid detection in drinking water

Responsive small-molecule fluorescence probe specific for target analyte detection is an emerging technology for food safety and quality analysis. In this work, we report a new water soluble small-molecule fluorescence probe (PG) for the detection of hypochlorous acid (HOCl) in drinking water samples. Probe PG was developed by coupling of a glucosamine into 10-methyl-10H-phenothiazine fluorophore with a HOCl-responsive C=N bond. The thioether is another recognition site that can be oxidized to be sulfoxide in water. Due to the specific reactions triggered by HOCl, probe PG’s absorption band is blue shifted from 388 to 340 nm, and fluorescence at 488 nm is more than 55-fold enhanced. Probe PG features high fluorescence stability in PBS buffer with varied pH, fast response and high selectivity to HOCl. The application of the probe PG for HOCl detection in real-world samples is demonstrated by HOCl detection in drinking water, including tap water, purified water, and spring water samples. The recoveries of this method for HOCl detection in drinking water are in the range of 99.17–102.3%. This work thus provides a new method for HOCl detection in drinking water with high precision and accuracy.

Development of iridium(III) phosphorescent probe for hypochlorous acid detection in macrophages cells and cancer cells co-culture system and application in inflamed mouse model

Macrophages infiltrated in tumor microenvironment (TME) were found to play vital roles in immune responses and tumor development. In the process of immune, macrophages could produce pro-inflammatory mediators including ROS. Thus, targeting macrophages related ROS and distinguishing macrophages and cancer cells in one or more types of tumor and tumor microenvironments is extremely important and necessary to better understand tumor-associated macrophages (TAMs) functions and provide new insights into macrophage-centred therapeutic. Herein, we developed two unique Ir(III) probes, Ir1 and Ir2, for HOCl detection. Because of the dual protection of C^N ligand, Ir2 exhibits high sensitivity and selectivity in the present of HOCl. Therefore, Ir2 can be employed to detect HOCl in flow cytometry and image exogenous and endogenous HOCl in mitochondria. Importantly, Ir2 was applied to distinguish macrophages cells and cancer cells in TAMs by flow cytometry. Moreover, Ir2 is applicable in staining five kinds of organs of mouse tissues and monitoring HOCl generation in the LPS-stimulated inflammation of mouse model with two-photon microscopy (TPM).

A ratiometric flavone-based fluorescent probe for hypochlorous acid detection with large Stokes shift and long-wavelength emission

A ratiometric fluorescent probe, FPT, was designed and synthesized for the selective and sensitive detection of hypochlorous acid (HClO) based on a flavone derivative under a single wavelength excitation. The addition of HClO to the solution of FPT induced a distinct fluorescence color change from orange to green. Probe FPT was successfully used to detect and image intracellular HClO in living zebra fish in a ratiometric manner.

An ultra-sensitive ratiometric fluorescent probe for hypochlorous acid detection by the synergistic effect of AIE and TBET and its application of detecting exogenous/endogenous HOCl in living cells.

An ultra-sensitive and ratiometric fluorescent probe for hypochlorous acid (HOCl) detection based on the mechanism of aggregation induced emission (AIE) and through-bond energy transfer (TBET) has been reported herein. By exploiting the advantages of AIE and TBET, which eliminates emission leakage from dark donors, the probe exhibits ultra-high sensitivity towards HOCl by an enhancement of over 7000-fold in the fluorescence ratio (I589 nm/I477 nm), which is one of the highest recorded so far. The reaction mechanism has been discussed in detail, and the effects of interferents and the reaction kinetics have also been investigated. Lastly, the successful result of exogenous/endogenous HOCl imaging detection in different cell lines indicates the potential use of the probe in living systems.

Development of a Selective Fluorescent Probe for Hypochlorous Acid Detection and Imaging

Development of a Selective Fluorescent Probe for Hypochlorous Acid Detection and Imaging

A benzothiazole-based fluorescent probe for hypochlorous acid detection and imaging in living cells

A benzothiazole-based turn-on fluorescent probe with a large Stokes shift (190nm) has been developed for hypochlorous acid detection. The probe displays prompt fluorescence response for HClO with excellent selectivity over other reactive oxygen species as well as a low detection limit of 0.08μM. The sensing mechanism involves the HClO-induced specific oxidation of oxime moiety of the probe to nitrile oxide, which was confirmed by HPLC-MS technique. Furthermore, imaging studies demonstrated that the probe is cell permeable and can be applied to detect HClO in living cells.

A fluorescein-based “turn-on” fluorescence probe for hypochlorous acid detection and its application in cell imaging

A simple fluorescent probe F-BH was designed and synthesized, introducing CN group which can be a recognition site for hypochlorous acid into the fluorescent probe molecule by using 2-benzothiazole hydrazone and formylated fluorescein. The fluorescence intensity of the probe F-BH solution was very weak, while the fluorescence of the solution was obviously enhanced and the color of the solution changed after the addition of ClO− ion. The selection and competition experiments proved that the probe has great selectivity for recognition of hypochlorous acid over other ROSs/RNSs and anions. Fluorescence titration experiments show that the probe has a low detection limit (17.5 nM). The probe has been successfully applied to real-time detection of hypochlorous acid in Hela cells.

A fast-response fluorescent probe for hypochlorous acid detection and its application in exogenous and endogenous HOCl imaging of living cells.

A facile fluorescent probe (NBD-DOP) has been developed to detect hypochlorous acid (HOCl) in this study. The probe consists of a NBD fluorophore and a dopamine moiety that reacts with HOCl specifically. The dopamine group quenches the fluorescence of NBD efficiently through a photoinduced electron transfer (PET) effect. Experimental data showed that NBD-DOP could detect HOCl with ultrafast response, high sensitivity and high selectivity in a wide pH range. The probe could also be used to detect the myeloperoxidase enzyme that produces HOCl. Moreover, NBD-DOP has been applied in the imaging of exogenous and endogenous HOCl in living cells by confocal fluorescence microscopy.

A high-resolution mitochondria-targeting ratiometric fluorescent probe for detection of the endogenous hypochlorous acid

Hypochlorite anion, one of the biologically important reactive oxygen species, plays an essential role in diverse normal biochemical functions and abnormal pathological processes. Herein, an efficient high-resolution mitochondria-targeting ratiometric fluorescent probe for hypochlorous acid detection has been designed, synthesized and characterized. It is easily synthesized by the condensation reaction (CC) of a 2-(2-hydroxyphenyl) quinazolin-4(3H)-one fluorophore and a cyanine group (mitochondria-targeting), which made the whole molecular a large Stokes shift (210nm) and the two well-resolved emission peaks separated by 140nm. As a result, it is considered as a good candidate for high resolution hypochlorous acid imaging in live cells. The ratiometric fluorescent probe exhibited outstanding features of high sensitivity, high selectivity, rapid response time (within 50s), and excellent mitochondria-targeting ability. Moreover, the probe can also be successfully applied to imaging endogenously hypochlorous acid in the mitochondria of living cells with low cytotoxicity, and high resolution.

An oxidative cleavage-based ratiometric fluorescent probe for hypochlorous acid detection and imaging

A new fluorescent molecule of an imidazole derivative was synthesized through simple cyclization of a hetero-aromatic compound and successfully applied for the rapid and ratiometric sensing of HOCl with high sensitivity and selectivity. It has also been demonstrated for the bioimaging of HOCl using A549 cells.

Oxidative Cleavage-Based Near-Infrared Fluorescent Probe for Hypochlorous Acid Detection and Myeloperoxidase Activity Evaluation

A near-infrared (NIR) fluorescent probe was synthesized and demonstrated to be highly selective in reaction with hypochlorous acid (HOCl), an endogenous reactive oxygen species (ROS) produced by myeloperoxidase in neutrophils. The reaction with HOCl resulted in the NIR fluorescence quenching at 774 nm and the absorbance decreasing at 710 nm, accompanied by the appearance of a new absorption band at 520 nm. The reaction mechanism was carefully examined and proposed to proceed by initial formation of chlorohydrins and subsequent degradation. This NIR fluorescent probe was successfully applied as a selective and sensitive indicator for HOCl on the basis of either colorimetry or fluorometry, which showed detection limits of 0.13 and 0.70 μM, respectively. In addition, the molecular probe was further demonstrated for NIR fluorescence imaging of HOCl in cells and for evaluating the enzymatic activity of myeloperoxidase in the HOCl generation by measuring absorbance change.