A seminaphthorhodafluor-based near-infrared fluorescent probe for hydrazine and its bioimaging in living systems

Cinnamyl Chalcone Based AIE Fluorescent Probes for Sensitive Detection of Hydrazine and its Application in Living Cells

Widely utilized in the chemical industry and agriculture, hydrazine is easily absorbed by living things and can cause physical harm when in touch for an extended period of time. As a result, a novel cinnamaldehyde chalcone C5 was produced by Friedel Crafts process and aldol condensation reaction. Triphenylamine was used as the raw material for hydrazine determination in both reactions. Chalcone C5 exhibits significant AIE behavior in a mixed mixture of ethanol and water in addition to having great selectivity and a low detection limit (0.119 nm) for hydrazine. The solvent effect test revealed a linear relationship between the Stokes shift of C5 in the solvent and the rise in solvent orientation polarization. It is important to note that C5 is not harmful to MCF-7 cells, mouse kidney cells, or pig kidney cells. Furthermore, research on cell imaging has demonstrated that probe C5 may be utilized to image the fluorescence of hydrazine in active MCF-7 cells.

Recent Advancements in the Design and Development of Near Infrared (NIR) Emitting Fluorescent Probes for Sensing and their Bio-Imaging Applications

Fluorescent bio-imaging will be the future in the medical diagnostic for visualising inner cellular and tissues. Near-infrared (NIR) emitting fluorescent probes serve dynamically for targeted fluorescent imaging of live cells and tissues. NIR imaging is advantageous because of its merits like deep tissue penetration, minimum damage to the tissue, reduced auto fluorescence from the background, and improved resolution in imaging. The Development of the NIR emitting probe was well explored recently and growing drastically. In this review, we summarise recent achievements in NIR probes in between 2018-2021. The merits and future applications have also been discussed in this review.

Seminaphthorhodafluor Derivatives Bridged Periodic Mesoporous Organosilicas for Detection of Cu2

Seminaphthorhodafluor (SNARF) Schiff base (SNARF-SB) bridged periodic mesoporous organosilicas (SSPMOs) with "turn-on" fluorescence enhancement for sensing Cu²⁺ were synthesized via a template-directed co-condensation method. Small-angle x-ray scattering (SAXS) patterns, high resolution transmission electron microscope (HRTEM) images, and N₂ adsorption-desorption isotherms indicated the presence of mesoporous structure in the SSPMOs. FT-IR spectra and ²⁹Si MAS NMR data confirmed the successful incorporation of bridged organic groups in the framework of SSPMOs. The luminous properties that SSPMOs had a selective response to Cu²⁺ were investigated by UV-Vis absorption spectroscopy and fluorescence spectroscopy. The limit of detection (LOD) was 5.1 × 10^-7 M and binding stoichiometry was determined 1:1 between SNARF-SB and Cu²⁺. The fluorescence enhancement of SSPMOs towards Cu²⁺ was induced by ring-opening of the spirolactam in SNARF-SB in framework of SSPMOs, which was confirmed by FT-IR spectra of SNARF-SB with Cu²⁺. Moreover, SSPMOs have improved fluorescence lifetimes compared with that of SNARF-SB. Therefore, SSPMOs can be a progressive chemical sensor for Cu²⁺ due to its high selectivity, recyclability, and stability.

Development of a ratiometric fluorescent probe with large Stokes shift and emission wavelength shift for real-time tracking of hydrazine and its multiple applications in environmental analysis and biological imaging

As a tremendously noxious and extensively utilized chemical reagent, hydrazine (N₂H₄) has become a serious threat to ecosystem and human health. Thus, it is desirable to exploit an efficient method for real-time tracking of hydrazine. Here, a novel ratiometric fluorescent probe PBQ-AB for hydrazine was rationally constructed from isolongifolanone. This probe displayed an extremely large Stokes shift of 230 nm and could selectively recognize hydrazine in the presence of other competitive species within an extremely short time ( 40 s). PBQ-AB also displayed some fascinating merits in the detection of hydrazine, including low detection limit (48 nM), wide pH range (5-12), excellent photostability (>240 min), and well-resolved emission wavelength shift (148 nm). Moreover, this probe was utilized to fabricate a ready-to-use electrospinning nanofibrous membrane for convenient detection of hydrazine vapor by virtue of smartphone. Furthermore, PBQ-AB was capable of determining hydrazine contaminant in environmental soil and water samples. Additionally, its favorable performance for detecting hydrazine was successfully demonstrated in live HeLa cells as well as in live Arabidopsis thaliana tissues, manifesting its promising application for labeling hydrazine in living systems. Therefore, we believed that this probe has great potential in environmental analysis and health supervision.

Construction of a mitochondria-targeted ratiometric fluorescent probe for monitoring hydrazine in soil samples and culture cells

Isoniazid and its major metabolite, hydrazine (N₂H₄), may interfere with mitochondrial function and have negative effects on cells. Consequently, an understanding of the role of N₂H₄ in mitochondria is highly desirable for protecting human health. Herein, we report a novel mitochondria-targeted ratiometric fluorescent probe (Mitro-N₂H₄) for N₂H₄ detection. Mitro-N₂H₄ exhibited an attenuation of green emission at 521 nm and an enhancement of yellow emission at 590 nm in the presence of N₂H₄ because of hydrazinolysis, indicating that it can be used as a ratiometric chemosensor for N₂H₄ with high selectivity and sensitivity. Such on-site monitoring of N₂H₄ vapour using test strips and N₂H₄-moistened soil analysis demonstrated its advantages in potential application for the convenient sensing of N₂H₄. Moreover, the rationally designed probe has many potential applications for imaging N₂H₄ produced in situ during the metabolism of isoniazid in living cells based on the ratio of the fluorescent signal.

A coumarin-fused 'off-on' fluorescent probe for highly selective detection of hydrazine

Hydrazine is a kind of widely used industrial raw material and a toxic biochemical reagent. Due to its toxic to organisms, hydrazine has been classified to be a hazardous environmental pollutant. It is urgent to develop fluorescent probe tools for selective sensitivity detection of hydrazine in the environment and the body. We developed here a new coumarin-based fluorescent probe for hydrazine detection. The probe can selectively detect hydrazine over other environmental and endogenous interfering analytes with a large off-on fluorescence response. The detection limit is 8.55 ppb, which is well below the allowed threshold limit value. The sensing mechanism is hydrazine-induced pyrazole ring formation, which is confirmed by HRMS and DFT calculation methods. Additionally, the probe could also be applied for hydrazine imaging in living HeLa cells.

The application of nitrogen heterocycles in mitochondrial-targeting fluorescent markers with neutral skeletons

Neutral fluorescent markers containing nitrogen heterocycles as targeting groups were designed and prepared to screen out structural units for targeting mitochondria.