A new Fe3+ fluorescent chemosensor based on aggregation-induced emission

An Ultra-low Detection Limit Fe3+ Optical Fiber Fluorescent Sensor Based on a Anti-B18H22 Derivative with Aggregation-induced Emission Enhancement

A fluorescent Fe3+ probe ((C10H7NO2)2B18H20, M1) by introducing two isoquinoline-1-carboxylic acid group into the 6,9-position of anti-B18H22 was designed and synthesized. The structure of M1 was investigated by 1H NMR, MS, FT-IR and theoretical calculation, and its optical properties were characterized with UV-Vis and PL. M1 showed aggregation induced emission enhancement (AIEE) properties in THF/H2O solution, and exhibited an excellent selectivity toward Fe3+ in THF/H2O (v/v, ƒw = 95%) solution with a detection limit of 1.93 × 10-5 M. The interaction mechanism of probe for detecting Fe3+ is attributed to the involvement of intramolecular charge transfer (ICT) process. Furthermore, a optical fiber fluorescent Fe3+ sensor based on M1 sensing film was developed, the detection limit of the optical fiber Fe3+ fluorescent sensor could be improved to13.8 pM, the ultra-low detection limit is superior to most reported fluorescent probes (or sensors) towards Fe3+. This method has the advantages of high sensitivity, anti-interference and easy to operate, and has great potential in the field of the analysis of environmental and biological samples.

Fabrication of Functional Polycatechol Nanoparticles

While low-dimensional (1D and 2D) polycatechol materials have been widely described for a range of biomedical and surface engineering applications, very few examples have been explored that focus on the construction of functional polycatechol nanoparticles. Herein, we report the facile fabrication of a series of polycatechol nanoparticles via a general and robust strategy based on the one-step oxidation reaction. IO₃^--induced catechol redox chemistry could facilitate the precise size control of the resulting nanoparticles and also allow the successful transfer and amplification of microscopic monomer function into macroscopic polycatechol material properties. The ease, facileness, and controllability of such a one-step fabrication process could highly promote the development of polycatechol nanomaterials for various applications.

Bis-biphenylacrylonitrile bridged with crown ether chain: a novel fluorescence sensor for Fe3+ in aqueous media

A novel fluorescence sensor for Fe³⁺ in aqueous media was developed and applied for living-cell imaging.

Tetraphenylethylene-Based AIE-Active Probes for Sensing Applications

This Review provides a comprehensive analysis of recent development in the field of aggregation-induced emission (AIE)-active tetraphenylethylene (TPE) luminophores and their applications in biomolecular science. It begins with a discussion of the diverse range of structural motifs that have found particular applications in sensing, and demonstrates that TPE structures and their derivatives have been used for a diverse range of analytes such as such as H⁺, anions, cations, heavy metals, organic volatiles, and toxic gases. Advances are discussed in depth where TPE is utilized as a mechanoluminescent material in bioinspired receptor units with specificity for analytes for such as glucose or RNA. The rapid advances in sensor research make this summary of recent developments in AIE-active TPE luminophores timely, in order to disseminate the advantages of these materials for sensing of analytes in solution, as well as the importance of solid and aggregated states in controlling sensing behavior.

Self-agglomerated crystalline needles harnessing ESIPT and AIEE features for the ‘turn-on’ fluorescence detection of Al3+ ions

We report the synthesis of probe 2 for the fluorescence “turn-on” detection of Al³⁺ ions in CH₃OH.

Graphene-Supported Spinel CuFe₂O₄ Composites: Novel Adsorbents for Arsenic Removal in Aqueous Media

A graphene nanoplate-supported spinel CuFe₂O₄ composite (GNPs/CuFe₂O₄) was successfully synthesized by using a facile thermal decomposition route. Scanning electron microscopy (SEM), high resolution transmission electron microscopy (HRTEM), Electron Dispersive Spectroscopy (EDS), X-ray diffraction (XRD) and X-ray Photoelectron Spectroscopy (XPS) were employed to characterize the prepared composite. The arsenic adsorption behavior of the GNPs/CuFe₂O₄ composite was investigated by carrying out batch experiments. Both the Langmuir and Freundlich models were employed to describe the adsorption isotherm, where the sorption kinetics of arsenic adsorption by the composite were found to be pseudo-second order. The selectivity of the adsorbent toward arsenic over common metal ions in water was also demonstrated. Furthermore, the reusability and regeneration of the adsorbent were investigated by an assembled column filter test. The GNPs/CuFe₂O₄ composite exhibited significant, fast adsorption of arsenic over a wide range of solution pHs with exceptional durability, selectivity, and recyclability, which could make this composite a very promising candidate for effective removal of arsenic from aqueous solution. The highly sensitive adsorption of the material toward arsenic could be potentially employed for arsenic sensing.

A highly selective and sensitive turn-on fluorescent probe for the detection of Al3+ and its bioimaging

A novel fluorescent sensor, 1-((2-hydroxynaphthalen-1-yl)methylene)urea (ocn) has been designed and applied as a highly selective and sensitive fluorescent probe for recognition of Al³⁺ in Tris-HCl (pH = 7.20) solution. The probe ocn exhibits an excellent selectivity to Al³⁺ over other examined metal ions, anions and amino acids with a prominent fluorescence 'turn-on' at 438 nm. ocn binds to Al³⁺ with a 2:1 binding stoichiometry and the detection limit was 0.3 μM. Furthermore, its capability of biological application was evaluated and the results showed that the sensor could be used to detect Al³⁺ in living cells.

Modulation of Intersystem Crossing Rate by Minor Ligand Modifications in Cyclometalated Platinum(II) Complexes

Photophysical properties of four new platinum(II) complexes comprising extended ppy (Hppy = 2-phenylpyridine) and thpy (Hthpy = 2-(2'-thienyl)pyridine) cyclometalated ligands and acetylacetonate (acac) are reported. Substitution of the benzene ring of Pt-ppy complexes 1 and 2 with a more electron-rich thiophene of Pt-thpy complexes 3 and 4 leads to narrowing of the HOMO-LUMO gap and thus to a red shift of the lowest energy absorption band and phosphorescence band, as expected for low-energy excited states of the intraligand/metal-to-ligand charge transfer character. However, in addition to these conventional spectral shifts, another, at first unexpected, substitution effect occurs. Pt-thpy complexes 3 and 4 are dual emissive showing fluorescence about 6000 cm(-1) (∼0.75 eV) higher in energy relative to the phosphorescence band, while for Pt-ppy complexes 1 and 2 only phosphorescence is observed. For dual-emissive complexes 3 and 4, ISC rates kISC are estimated to be in order of 10(9)-10(10) s(-1), while kISC of Pt-ppy complexes 1 and 2 is much faster amounting to 10(12) s(-1) or more. The relative intensities of the fluorescence and phosphorescence signals of Pt-thpy complexes 3 and 4 depend on the excitation wavelength, showing that hyper-intersystem crossing (HISC) in these complexes is observably significant.

Supramolecular aggregates as sensory ensembles

Recent research progress in sensing based on induced supramolecular aggregation or disaggregation.

An aggregation-induced emission star polymer with pH and metal ion responsive fluorescence

A one-pot strategy from ring-opening metathesis polymerization was employed to prepare AIE-active star polymers, which were designed to have multi-responsive fluorescence to varied stimuli including pH, CO₂, and metal ions.

A Simple Fluorescence Probe Based on Aggregation-Induced Emission (AIE) Property for the Detection of Mg(2+) Ions

A simple aggregation-induced emission-based fluorescence probe (1) for Mg(2+) was synthesized by condensation of benzene-1, 2-diamine with 5-bromo-2-hydroxybenzaldehyde, This compound shows favourable character of the AIE-active molecules. More importantly, after addition of Mg(2+) to probe (1) in acetonitrile, the solution changed from colorless to yellow colour solution under ultraviolet (UV) radiation obtained from hand-held UV lamp, this finding suggested that probe (1) can be used to detect Mg(2+) by colorimetric detection. Detection limit can reach 2.31 × 10(-5) M(-1). The practical value of the selective and sensitive fluorescence indicators was confirmed by its application to detection of magnesium ion in acetonitrile.

A novel triple-mode fluorescent pH probe from monomer emission to aggregation-induced emission

A tetraphenylenlene (TPE)-based fluorescent probe could selectively monitor pH in THF–H₂O media in wide-range pH. From acidic to basic conditions, it displayed monomer emission, ratiometric fluorescence and aggregation-induced emission successively.

Amine functionalized tetraphenylethylene: a novel aggregation-induced emission based fluorescent chemodosimeter for nitrite and nitrate ions

A novel AIE-based fluorescent probe for the detection of trace amounts of nitrite and nitrate ions in water has been developed, which spontaneously detects nitrites (or nitrates) by a fluorescence “turn-off” method.

An aggregation-induced emission based “turn-on” fluorescent chemodosimeter for the selective detection of Pb2+ ions

An aggregation-induced emission (AIE) based “turn-on” fluorescent chemodosimeter for selective detection of Pb²⁺ ions has been developed. The probe is a phosphate functionalized tetraphenylethylene derivative and the resulting lead–TPE complex has very low solubility in working solvent and triggers AIE and shows a low detection limit of 10 ppb.