Search

Hypochlorous acid (HOCl) acts as crucial roles in pathologica processes and relevant diseases. Thus, it is meaningful to explore a reliable method for monitoring HClO in biosystem. In this work, a ratiometric fluorescent probe 2-(benzo d thiazol-2-yl)-4-(methylthio)phenol (BTMSP) has been constructed for HClO by adopting ICT-ESIPT strategy. The probe possessed itself red fluorescence due to the electron-donating capability of sulfur atom and showed remarkable blue fluorescence response to HClO by oxidizes the sulfur atom to a sulfoxide. The ratiometric probe exhibited highly specific, rapid response and excellent sensitivity toward HClO as well as a low detection limit (4.2 × 10−7 M). Moreover, the ratiometric probe showed well-separated dual emission (450/580), and a large pseudo Stokes shift (190 nm). In addition, the probe was used for the imaging of HClO with satisfying results. Unlabelled Image • A simple fluorescent probe for HOCl has been synthesized by on step reaction. • Ratiometric detection of HOCl through modulation of ICT-ESIPT dual mechanisms • Well-separated dual emission (450/580 nm) and large pseudo Stokes shift (190 nm) • The probe could be used to monitor HOCl in live cell. [ABSTRACT FROM AUTHOR]

Thiophenol has a broad application in agriculture and industry. However, thiophenol can harm to the environment and health for its high toxicity. Developing an effective method for detection of thiophenol in the field of environmental and biology is valuable. In this work, we construct a reaction-based ratiometric fluorescent probe (E)-4-(2-(7-(diethylamino)-2-oxo-2H-chromen-3-yl)vinyl)-1-(4-(2,4-dinitrophenoxy)benzyl)pyridin-1-ium bromide (DCVP-DNP) for probing thiophenol in environment and cells by employing (E)-7-(diethylamino)-3-(2-(pyridin-4-yl)vinyl)-2H-chromen-2-one (DCVP) as the fluorophore and 2,4-dinitrophenyl (DNP) ether as the recognition group for the first time. The probe has high selectivity for thiophenol though thiophenol-triggered nucleophilic substitution reaction. In addition, the ratio of emission intensities of the probe has linearly with thiophenol concentration in the range of 0–65 μM and the detection limit of thiophenol is as low as 4.8 × 10−8 M. Moreover, the probe can not only be applied for detection of thiophenol in water samples, but also image thiophenol in living cells, suggesting its potential application in environment and biological system. Unlabelled Image • A coumarin fluorescent probe for detection of thiophenol was synthesized. • The probe exhibited ratiometric emission and a large pseudo-Stokes shift with a low detection limit. • The probe has been successfully used for thiophenol detection in real water samples and in living cells. [ABSTRACT FROM AUTHOR]

Peroxynitrite (ONOO−) is a primary kind of reactive oxygen species. Excessive ONOO− can induce oxidative damage to biomolecules and further results in various diseases. So, quantitative monitoring ONOO− with excellent selectivity and sensitivity is imperative for elucidating its role in biological processes. In this study, a novel pyridinium fluorescent ONOO− probe (CPC) has been constructed base on ICT-modulated by combining coumarin fluorophore and diphenylphosphinate recognition group. The fluorescence response of CPC for ONOO− is realized via the removal of diphenylphosphinate group. The probe CPC shows prominent features for detection of ONOO− including fast response rate (within 3 min), excellent selectivity and sensitivity, distinct colorimetric (red to green), and a large emission wavelength shift (105 nm). The emission intensity ration (I 538 /I 643) exhibits 153-fold enhancement along with the increasing ONOO− and the detection limit is as low as 1.60 × 10−8 M. These good response properties make CPC possible to quantitative detection of ONOO− concentration. By using the strategy, the ratiometric CPC has been employed to detection of mitochondrial ONOO− in live cell successfully. Unlabelled Image • A novel ratiometric pyridinium fluorescent ONOO− probe was synthesized. • The probe exhibited fast response, ratiometric, excellent selectivity and sensitivity detection of ONOO−. • The probe could be used to employ to ratiometric detection of mitochondrial ONOO− in live cell. [ABSTRACT FROM AUTHOR]

Developing specific and sensitive method for endogenous peroxynitrite (ONOO−) in living systems is valuable to understand its various pathological events. In this work, a simple and novel fluorescent probe (HPP) based on aggregation induced emission (AIE) as well as excited state intramolecular proton transfer (ESIPT) processes for endogenous ONOO− detection was constructed containing a diphenylphosphinate as the reactive site and a salicylaldehyde azine as the fluorophore. The probe showed specific fluorescence turn-on response toward ONOO− owing to the diphenylphosphinate group of HPP reacted with ONOO−, releasing the salicylaldehyde azine with both AIE and ESIPT characteristics. In addition, the probe exhibited a large Stokes shift, an excellent light-up ratio, high selectivity and excellent sensitivity with a low detection limit of 8 × 10−8 M for endogenous ONOO−. Moreover, the probe could be applied to bioimaging of endogenous ONOO− in live cell, which demonstrated the probe can be used as effective tool for investigation of ONOO− in biological systems. Unlabelled Image • A novel and simple AIE-ESIPT fluorescent probe was designed and synthesized. • The probe exhibited a large Stokes shift, excellent selectivity and sensitivity for ONOO−. • The probe could be applied to bioimaging of endogenous ONOO− in live cell. [ABSTRACT FROM AUTHOR]

[Display omitted] • A novel "ESIPT + AIE" based biosensor was fabricated. • It showed a fast (6 s) and ultrasensitive (5.1 nM) response to ONOO− with wide pH value adaptation (3–10). • It was able to visualize ONOO− in living cells with low cytotoxicity. Peroxynitrite (ONOO−) is a highly reactive and short-lived oxidant with low content in cells, and plays an important role in biology. Accordingly, developing a rapid, sensitive, and effective detection approach of cellular ONOO− is very meaningful to further study its biological functions. In this work, a new biosensor BQ for the recognition of ONOO− was facilely synthesized by condensation of 2-hydrazinoquinoline and formylated benzothiazole possessing "ESIPT + AIE" feature. The probe can be used in a wide range of pH value, and displayed a rapid fluorescence "turn on" response toward ONOO− with low detection limit (5.1 nM) and high selectivity over other competitive substances through ONOO−-triggered oxidative cleavage of C=N double bond. The sensing mechanism of BQ towards ONOO− was proved by 1HNMR and HRMS analysis. Furthermore, the capacity of BQ to detect intracellular ONOO− has been well-demonstrated by fluorescence microscopic imaging experiments, indicating its potential application for investigating the physiological function of ONOO−. [ABSTRACT FROM AUTHOR]

[Display omitted] • A new colorimetric and far-red fluorescent probe for HSO 3 − was developed. • It showed 100% water soluble, fast response, and high selectivity to HSO 3 −. • The probe could detect HSO 3 − on paper strips and visualize HSO 3 − in living cell. Bisulfite (HSO 3 −) and sulfite (SO 3 2−) are involved in numerous physiological processes of living systems. However, high levels of these substances are often correlated to many diseases. Herein, we designed and synthesized a simple full water-soluble colorimetric and far-red fluorescent probe (E)-1-methyl-4-(2-(1-methylquinolin-1-ium-3-yl)vinyl)quinolin-1-ium iodide trifluoromethanesulfonate (DQ) for HSO 3 −/SO 3 2− detection by coupling 1,4-dimethylquinolinium with 3-quinolinium carboxaldehyde for the first time. The probe DQ showed high selectivity for HSO 3 − detection via a 1,4-nucleophilic addition reaction with distinct color changes from colorless to purple-red and remarkable far-red fluorescence enhancement in pure aqueous solutions. Specifically, the probe displayed a fast response (<15 s) for bisulfite, which renders it suitable for real time detection of HSO 3 −. Under the optimized conditions, the far-red fluorescence intensity was linear to the concentrations of HSO 3 − in the range from 0 to 25 μM and the detection limit was as low as 0.11 μM. Additionally, the probe could be applied to sense HSO 3 − on paper strips, real sample including vermicelli and sugar and image HSO 3 − in living cells, which indicated that probe DQ has potential application in food samples and living systems. [ABSTRACT FROM AUTHOR]