Fluorescent Disulfide-functional Coordination Polymers for Sensitive Detection of Hydrogen Peroxide

Fluorescein Derivative Immobilized Optical Hydrogels: Fabrication and Its Application for Detection of H2O2

A novel fluorescein-based probe FLA-Boe was developed for detecting H₂O₂. Modified by 2-Bromomethylphenylboronic acid pinacol ester, FLA-Boe is a Fluorescein derivative with eminent photostability and remarkable H₂O₂ sensitivity and selectivity. FLA-Boe was utilized to synthesize hydrogel sensors in the manner of guest–host interaction by taking advantage of its aforementioned features. The hydrogel sensor can be used to detect H₂O₂ effectively in both flowing and static water environments with satisfactory performance. It is expected that this application may open a new page to develop a neoteric fluorescent property analysis method aiming at H₂O₂ detection.

Evaluate the bisphenol A-induced redox state in cells, zebrafish and in vivo with a hydrogen peroxide turn-on fluorescent probe

Hydrogen peroxide (H₂O₂) is an important active oxygen species that plays a major role in redox balance and in physiological and pathological processes of various diseases of biological systems. As H₂O₂ is an endogenous active molecule, fluctuations in H₂O₂ content are not only affected by the state of biological system itself but also easily affected by Bisphenol A (BPA, a typical estrogenic environmental pollutant) in the external environment. Here, the near-infrared fluorescent probe Cy-NOH2 (λ_em = 750 nm) as a tool was synthesized to detect fluctuations in H₂O₂ content in cells and organisms induced by BPA. High sensitivity and excellent selectivity were found when the probe Cy-NOH2 was used to monitor endogenous H₂O₂ in vitro. In addition, the expression of H₂O₂ induced by different concentrations of BPA was able to be detected by the probe. Zebrafish and mice models were induced with different concentrations of BPA, and the H₂O₂ content showed significant increasing trends in zebrafish and livers of mice with increasing BPA concentrations. This study reveals that the probe Cy-NOH2 can be used as an effective tool to monitor the redox state in vivo under the influence of BPA, which provides a basis for clarifying the mechanisms of BPA in a variety of physiological and pathological processes.

A Novel Ratiometric Cationic Iridium(III) Complex Phosphorescent Probe for Hydrogen Peroxide

A novel cationic iridium(III) complex phosphorescent probe (Ir-BE) containing aromatic boronate ester moiety as recognition unit was designed and synthesized. The probe exhibits ratiometric emission variations (I₄₉₀/I₅₅₀) with the color change from yellow to green only toward H₂O₂ with a broad pH range of 4 - 13. Different from other aromatic boronate-based probes, Ir-BE possesses larger Stokes shift (320 nm) and exhibits good linear correlation (R² = 0.998) between the emission ratio (I₄₉₀/I₅₅₀) and the H₂O₂ concentration in a range of 0 - 300 μM. The detection limit was as low as 0.21 μM. Furthermore, the real water sample studied further proved Ir-BE has excellent selectivity for the quantitative detection of H₂O₂.

Zeolitic imidazolate frameworks for use in electrochemical and optical chemical sensing and biosensing: a review

This review (with 145 refs.) summarizes the progress that has been made in the use of zeolitic imidazolate frameworks in chemical sensing and biosensing. Zeolitic imidazolate frameworks (ZIFs) are a type of porous material with zeolite topological structure that combine the advantages of zeolite and traditional metal-organic frameworks. Owing to the structural flexibility of ZIFs, their pore sizes and surface functionalization can be reasonably designed. Following an introduction into the field of metal-organic frameworks and the zeolitic imidazolate framework (ZIF) subclass, a first large section covers the various kinds and properties of ZIFs. The next large section covers electrochemical sensors and assays (with subsections on methods for gases, electrochemiluminescence, electrochemical biomolecules). This is followed by main sections on ZIF-based colorimetric and luminescent sensors, with subsections on sensors for metal ions and anions, for gases, and for organic biomolecules. The last section covers SERS-based assays. Several tables are presented that give an overview on the wealth of methods and materials. A concluding section summarizes the current status, addresses current challenges, and gives an outlook on potential future trends. Graphical abstract In recent years, ZIFs and their composites have been widely used as probes in chemical sensing, and these probes have shown great advantages over other materials. This review describes the current progress on ZIFs toward electrochemical, luminescence, colorimetric, and SERS-based sensing applications, highlighting the different strategies for designing ZIFs and their composites and potential challenges in this field.

A New Fluorescent Turn-on Dual Interaction Position Probe for Determination of Hydrazine

Hydrazine is an important catalyst and chemical raw material. But it is highly toxic and potentially carcinogenic. We designed a new hydrazine probe based on a synergistic effect by introducing acetate and phthalimide into 2-phenyl-benzimidazole (PBI). Comparative experiments proved that "the dual position interaction" had a "synergistic effect" on fluorescence enhancement. The fluorescence enhancement caused by the probe (15.0 fold) is much larger than the sum of the fluorescence enhancement of the two monomer compounds (2.6 and 1.4 folds, respectively). A theoretical calculation showed an inhibition of the PET process and a recovery of the ICT process led to a fluorescence enhancement. The probe was specific to hydrazine and showed a linear response to it in the concentrations range of 0.2 - 200 μM with a LOD of 0.062 μM (1.99 ppb). Moreover, the probe could detect hydrazine in tap water; the recovery of hydrazine from the tap water was between 98.86 - 103.28%.