Novel magnetite nanoparticle based on BODIPY as fluorescent hybrid material for Ag(I) detection in aqueous medium

Synthesis, characterization, and application of novel fluorescent sporopollenin for effective detection of mercury (II) ions from aqueous media

In this investigation, a novel environmentally friendly functionalized fluorescent Sp-TAB hybrid material was advanced for the sensitive detection of environmentally polluting Hg(II). The characterization of the synthesized fluorescent Sp-TAB hybrid material using SEM and EDX provided insights into morphological and structural changes in the material's pore structure, while XRD and FT-IR analyses revealed the impact of the prepared material at each stage. Optimal parameters such as temperature, contact time, and pH influencing Hg(II) ion detection were determined. Application of the fluorescent Sp-TAB hybrid material was determined a detection limit (LOD) of 4.87 μM for Hg(II) ions. This study shows the potential of the immobilization-enhanced fluorescent Sp-TAB hybrid material for sensitive Hg(II) ion detection in tap water. Additionally, this study is believed to serve as a model for sensitive and practical detection applications of heavy metals in the future.

Imidazole Compounds: Synthesis, Characterization and Application in Optical Analysis

Imidazole is a five-membered heterocyclic ring containing three carbon atoms, two nitrogen atoms, and two double bonds. Among two nitrogen atoms, one of which carries with a hydrogen atom is a pyrrole-type nitrogen atom, another is a pyridine type nitrogen atom. Hence, the imidazole ring belongs to the π electron-rich aromatic ring and can accept strong suction to the electronic group. Moreover, the nitrogen atom of the imidazole ring is coordinated with metal ions to form metal-organic frameworks. In recent years, because of imidazole compounds' unique optical properties, their applications have attracted more and more attention in optical analysis. Thus, this review has summarized the synthesis, characterization, and application with emphasis on the research progress of imidazole compounds in optical analysis, including fluorescence probe, colorimetric probe, electrochemiluminescence sensor, fiber optical sensor, surface plasmon resonance, etc. This paper will suggest the direction for the development of imidazole-containing sensors with high sensitivity and selectivity.

A new bodipy/pillar[5]arene functionalized magnetic sporopollenin for the detection of Cu(II) and Hg(II) ions in aqueous solution

In this study, a new bodipy/pillar[5]arene functionalized magnetic MS-Sp-P[5]-bodipy microcapsule sensor was prepared based on the use of environmentally friendly for the selective and sensitive detection of Cu(II) and Hg(II) ions in aqueous media. SEM results used in the characterization process of the materials synthesized at each stage confirmed the structural and morphological changes in the pore structure, while other characterization results (FT-IR and XRD) elucidated the role of pillar[5]arene compound and bodipy dye in the synthesis of magnetic microcapsule sensors. The colloidal solution of MS-Sp-P[5]-bodipy (water/ethanol)) showed two fluorescence bands centered at 402 and 540 nm. The detection limits of MS-Sp-P[5]-bodipy for Hg(II) and Cu(II) were calculated to be 0.06 µM and 2.27 µM, respectively (at 540 nm). The linear range of the magnetic sensor for Hg(II) and Cu(II) was found to be in the range of 1-150 µM and 10-150 µM, respectively. The experimental results (response time, pH, temperature, sensitivity and selectivity) demonstrated the applicability and potential of the prepared magnetic microcapsule sensor for the detection of Cu(II) and Hg(II) in water and tap water samples containing heavy metal ions.

Fluorescence sensing and adsorption kinetics of Gd-doped AgInS2 I-III-VI quantum dots - A case study of Ag+ ions interactions

The poor fluorescence properties of magneto-fluorescent paramagnetic-ion (Gd, Mn, or Co) doped I-III-VI quantum dots (QDs) at higher paramagnetic-ion doping concentrations have limited their use in magnetic-driven water-based applications. This work presents, for the first time, the use of stable magneto-fluorescent Gd-doped AgInS2 QDs at high Gd mole ratios of 16, 20, and 30 for the fluorescence detection and adsorption of Ag+ ions in water environments. The effect of pH, initial concentration, contact time, and adsorbent dosage were systematically evaluated. The AgInS2 QDs with the least Gd mole ratio (16) exhibited the best fluorescence characteristics (LOD = 0.88, R2 = 0.9549) while all materials showed good adsorption properties under optimized conditions (pH of 2, initial concentration of 30 ppm, contact time of 10 min and adsorbent dosage of 0.02 g) and a pseudo 2nd order reaction was followed. The adsorption mechanism was proposed to be a combination of ion-exchange, electrostatic interaction, complexation, and diffusion processes. Application in environmental wastewater samples revealed complete removal of Ag + ions alongside Ti2+ Pb2+, Ni2+, Cr3+, and Zn2+ ions.

The Influence of Alkali Metals on the Doping of Poly(p-phenylene) Oligomers

In this study, we report on crystallographic studies that were performed on Na- and K-doped terphenyl and quaterphenyl. The data obtained via X-ray scattering and transmission electron diffraction show that, for both K-doped terphenyl and quaterphenyl samples, there is an increase in the c parameter. However, in regard to Na-doped terphenyl, there is a c parameter decrease along with an a parameter increase, which may be accounted for by the polymerization of this oligomer. Moreover, in order to complete the crystallographic study, a Raman analysis was conducted to describe the localization of the radical anions and the local distortions induced by the electric charges during the doping process.

"Killing two birds with one stone": A fluorescent hybrid nanoparticle modified with BODIPY for efficiently detection and removal of toxic Cu (II) ion from aqueous solutions

In this paper, we successfully synthesized a fluorescent hybrid material (f-Silica gel) for the removal and recognition of cations. A Bodipy derivative was used as a source of fluorescent material. The characterization of Bodipy derivative and the modified surfaces were performed by some techniques like NMR, XRD, SEM, and FT-IR. The spectroscopic studies (complex stoichiometry, pH effect, response time) were carried out with fluorescence spectroscopy for the sensitive and selective recognition of Cu (II) ions. The LOD (limit of detection) was calculated as 4.63 μM and the most optimum response time was determined as 25 min. Moreover, the complex interaction between f-Silica gel and Cu (II) ions stables generally in the range of pH: 1-12. f-Silica gel can be also used as a solid support surface to remove Cu (II) ions from the wastewater. The adsorption kinetics and isotherms of Cu (II) on the f-Silica gel were determined with several parameters such as the amount of adsorbent, temperature, and pH. Langmuir adsorption isotherm model was performed for the adsorption of Cu (II) ions and the maximum capacity was found to be 19. 920 mg/g. The kinetic data ensured that the R² value was obtained as 0.9941 from the kinetic model (pseudo-second-order). Thus, it is very close to the desired value (1) and the value of q_e(expe) is very close to the value of q_e(calc). The thermodynamic results support the spontaneous, random, and endothermic adsorption process. All results indicated that the hybrid material can be used as both a sensor and an adsorbent for the detection and removal of Cu (II) ions in environmental processes.

Importance of BODIPY-based Chemosensors for Cations and Anions in Bio-imaging Applications

Background:

Chemosensor compounds are useful for sensitive selective detection of cations and anions with fluorophore groups in an attempt to develop the effective selectivity of the sensors. Although familiar fluorescent sensors utilizing inter-molecular interactions with the cations and anions, an extraordinary endeavor was executed the preparation of fluorescent-based sensor compounds. 4,4-difluoro-4- bora-3a,4a-diaza-s-indacene (Bodipy) and its derivatives were firstly used as an agent in the imaging of biomolecules due to their interesting structures, complexation, and fluorogenic properties. Among the fluorescent chemosensors used for cations and anions, Bodipy-based probes stand out owing to the excellent properties such as sharp emission profile, high stability, etc. In this review, we emphasize the Bodipy-based chemosensor compounds, which have been used to image cations and anions in living cells, because of as well as the biocompatibility and spectroscopic properties.

Methods:

Research and online content related to chemosensor online activity is reviewed. The advances, sensing mechanisms and design strategies of the fluorophore exploiting selective detection of some cation and anions with Bodipy-based chemosensors are explained. It could be claimed that the using of Bodipy-based chemosensors is very important for cations and anions in bio-imaging applications.

Results:

Molecular sensors or chemosensors are molecules that show a change can be detected when affected by the analyte. They are capable of producing a measurable signal when they are selective for a particular molecule. Molecular and ion recognition that it is important in biological systems such as enzymes, genes, environment, and chemical fields. Due to the toxic properties of many heavy metal ions, it is of great importance to identify these metals due to their harmful effects on living metabolism and the pollution they create in the environment. This process can be performed with analytical methods based on atomic absorption and emission. The fluorescence methods among chemosensor systems have many advantages such as sensitivity, selectivity, low price, simplicity of using the instrument and direct determination in solutions. The fluorescence studies can be applied at nanomolar concentrations.

Conclusion:

During a few decades, a lot of Bodipy-based chemosensors for the detection of cations & anions have been investigated in bio-imaging applications. For the Bodipy-based fluorescent chemosensors, the Bodipy derivatives were prepared by different ligand groups for the illumination of the photophysical and photochemical properties. The synthesized Bodipy-based chemosensors have remarkable photophysical properties, such as a high quantum yield, strong molar absorption coefficient etc. Moreover, these chemosensors were successfully implemented on living organisms for the detection of analytes.

Nanofibrous ε-polycaprolactone scaffolds containing Ag-doped magnetite nanoparticles: Physicochemical characterization and biological testing for wound dressing applications in vitro and in vivo

Skin wounds can lead to numerous complications with dangerous health consequences. In this work, magnetite nanoparticles were doped with different concentrations of antimicrobial silver (Ag) ions and incorporated into the electrospun nanofibrous ε-polycaprolactone (PCL) scaffolds. Nanoparticles and scaffolds with various Ag contents were characterized using a range of physicochemical techniques. Ag entered magnetite as cations and preferentially positioned at tetrahedral sites, introducing lattice distortions and topographic irregularities. Amorphization of the structure due to accommodation of Ag expanded the lattice in the bulk and contracted it on the surface, where broadened distribution of Fe-O coordinations was detected. Promoting spin canting and diminishing the double exchange interaction through altered distribution of ferric and ferrous ions, Ag softened the magnetism of magnetite. By making the nanoparticle structure more defective, Ag modified the interface with the polymer and promoted the protrusion of the nanoparticles from the surface of the polymeric nanofibers, thus increasing their roughness and hydrophilicity, with positive repercussions on cell adhesion and growth. Both the viability of human melanocytes and the antibacterial activity against E. coli and S. aureus increased with the concentration of Ag in the magnetite phase of the scaffolds. Skin wound healing rate in rats also increased in direct proportion with the concentration of Ag in the magnetite phase, and no abnormalities in the dermal and epidermal tissues were visible on day 10 in the treatment group. These results imply an excellent potential of these composite nanofibrous scaffolds for use as wound dressings and in other reconstructive skin therapies.

Two Novel BODIPY-Functional Magnetite Fluorescent Nano-Sensors for Detecting of Cr(VI) Ions in Aqueous Solutions

In this study, we developed two different very sensitive magnetite fluorescent Fe₃O₄@SiO₂-TPED-BODIPY and Fe₃O₄@SiO₂-TMPTA-BODIPY nano-sensors for the selective detection of Cr(VI) ions. The Cr(VI) metal ions sensing is based on the fluorescent quenching of BODIPY functionalized with Fe₃O₄@SiO₂-TPED and Fe₃O₄@SiO₂-TMPTA nanoparticles in the ethanol-water environment. Characterization of the newly synthesized fluorescent BODIPY compound was performed on a ¹H and ¹³C-NMR spectrometer. The morphology, chemical and physical properties of the sensing nano-sensors were studied by transmission thermogravimetric analysis (TGA), X-ray diffraction (XRD), energy dispersive X-ray (EDX), scanning electron microscopy (SEM), FT-IR spectroscopy, and transmission electron microscopy (TEM). UV-visible and fluorescent spectroscopy were used to characterize BODIPY functionalized magnetite fluorescent nano-sensors. Characterization measurements revealed that the mean particle diameter of magnetite fluorescent Fe₃O₄@SiO₂-TPED-BODIPY and Fe₃O₄@SiO₂-TMPTA-BODIPY nano-sensors was 18.5 and 19 nm, respectively. The magnetite fluorescent Fe₃O₄@SiO₂-TPED-BODIPY and Fe₃O₄@SiO₂-TMPTA-BODIPY nano-sensors (0.1 gL^-1 in EtOH/H₂O, v/v (3/7)) showed fluorescence quenching responses towards Cr(VI) ions in the medium at pH:1. The fluorescence quenches of the magnetite fluorescent Fe₃O₄@SiO₂-TPED-BODIPY and Fe₃O₄@SiO₂-TMPTA-BODIPY nano-sensors by Cr(VI) were completed in first 5 and 3 min. Respectively. These features provide potential uses of BODIPY functionalized magnetite fluorescent nano-sensors (Fe₃O₄@SiO₂-TPED-BODIPY and Fe₃O₄@SiO₂-TMPTA-BODIPY) as a new class of non-toxic sensors for environmental applications. Graphical Abstract.

A Water-Soluble Fluorescent Probe for the Selective Sensing of Ag+ and its Application in Imaging of Living Cells and Nematodes

In this study, an imidazole-coumarin based fluorescent probe was developed for the selective and sensitive detection of Ag⁺ in aqueous solution. Using a combination of Job plot, NMR titrations, and DFT calculations, the binding properties between Ag⁺ and the probe were deeply investigated, and the results revealed a 1:1 binding stoichiometry between the probe and Ag⁺ with a binding constant of 1.02 × 10⁶ M^-1. The detection limit was found to be 150 nM, which satisfies the requirement for the quantitative detection of Ag⁺ in real water samples. Moreover, the new probe, Ic, was successfully applied to sense Ag⁺ in HeLa and HepG2 cells as well as in C. elegans, indicating that it could be a useful tool for the environmental monitoring of Ag⁺ pollution. These results demonstrated that Ic could serve as a high-efficiency and low-cost fluorescent probe for tracking Ag⁺ in an aquatic environment and biological organisms.

A Sensitive Near-Infrared Fluorescent Probe for Detecting Heavy Metal Ag⁺ in Water Samples

Silver is a common catalyst in industrial production, and the frequent use of Ag⁺ can cause water pollution. Thus, the detection of Ag⁺ in the environment is necessary to determine the level of pollution from silver. In this work, we designed a new, highly selective near-infrared (NIR) fluorescent probe QCy to detect Ag⁺. The probe exhibits "turn-off" fluorescence quenching responses at 760 nm towards Ag⁺ over other relevant cations, with outstanding sensitivity and a low detection limit (0.03 µM), which is considerably lower than the standard of the World Health Organization (WHO) for drinking water (0.9 µM). Meanwhile, QCy showed a very good linearity at a low concentration of Ag⁺ with a 'naked eye' visible color change of solution from blue to red. The probe has been applied successfully for the detection of Ag⁺ in real water samples.

Bodipy-based chemosensors for highly sensitive and selective detection of Hg2+ ions

Small molecular chemo-sensors with strong fluorescence were designed and synthesized. Then, corresponding macromolecular sensors were synthesized by introducing the as-prepared small molecular sensors. The macromolecular chemo-sensors not only retained their sensing ability, but also enhanced the sensing ability dramatically.

Recent Advances of Electrospun Nanofibrous Membranes in the Development of Chemosensors for Heavy Metal Detection

It is critical to detect and analyze the heavy metal pollutions in environments and foods. Chemosensors have been widely investigated for fast detection of analytes such as heavy metals due to their unique advantages. In order to improve the detection sensitivity of chemosensors, recently electrospun nanofibrous membranes (ENMs) have been explored for the immobilization of chemosensors or receptors due to their high surface-to-volume ratio, high porosity, easiness of fabrication and functionalization, controllability of nanofiber properties, low cost, easy detection, no obvious pollution to the detection solution, and easy post-treatment after the detection process. The purpose of this review is to summarize and guide the development and application of ENMs in the field of chemosensors for the detection of analytes, especially heavy metals. First, heavy metals, chemosensors, and four types of preparation methods for ENM-immobilized chemosensors/receptors are briefly introduced. And then, ENM-immobilized chemosensors/receptors and their application progresses for optical, electro, and mass detections of heavy metals are reviewed according to the four types of preparation methods. Finally, the application of ENM-immobilized chemosensors/receptors is summarized and an outlook is provided. The review will provide an instruction to the research and development of ENM-immobilized chemosensors/receptors for the detection of analytes.