Luminescence Enhancement after Adding Stoppers to Europium(III) Nanozeolite L

Surface functionalization of hydroxyapatite nanoparticles for biomedical applications

This review completely covers the various aspects of hydroxyapatite (HAp) nanoparticles and their role in different biological situations, and provides the surface and interface contents on (i) hydroxyapatite nanoparticles and their hybridization with organic molecules, (ii) surface designing of hydroxyapatite nanoparticles to provide their biocompatibility and photofunction, and (iii) coating technology of hydroxyapatite nanoparticles. In particular, we summarized how the HAp nanoparticles interact with the different ions and molecules and highlighted the potential for hybridization between HAp nanoparticles and organic molecules, which is driven by the interactions of the HAp nanoparticle surface ions with several functional groups of biological molecules. In addition, we highlighted the studies focusing on the interfacial interactions between the HAp nanoparticles and proteins for exploring the enhanced biocompatibility. Such studies focus on how these interactions affect the hydration layers and protein adsorption. However, the hydration layer state involves diverse molecular interactions that can alter the shape of the adsorbed proteins, thereby affecting cell adhesion and spreading on the surfaces. We also summarized the relationship between the surface properties of the HAp nanoparticles and the hydration layer. Furthermore, we spotlighted the cytocompatible photoluminescent probes that can be developed by designing HAp/organic nanohybrid structures. We then emphasized the importance of photofunctionalization in theranostics, which involves the integration of diagnostics and therapy based on the surface design of the HAp nanoparticles. Furthermore, the coating techniques using HAp nanoparticles and HAp nanoparticle/polymer composites were outlined for fusing base biomaterials with biological tissues. The advantages of HAp/biocompatible polymer composite coatings include the ability to effectively cover porous or irregularly shaped surfaces while controlling the thickness of the coating layer, and the addition of HAp nanoparticles to the polymer matrix improves the mechanical properties, increases the roughness, and forms the morphologies that mimic bone nanostructures. Therefore, the fundamental design of hydroxyapatite nanoparticles and their surfaces was suggested from various aspects for biomedical applications.

Boosting the Luminescence of a Europium(III)-β-Diketonate Complex-Nanoclay Aqueous Solution by Acetylcholine

It is a challenging task to prepare lanthanide complex-based luminescent materials with high quantum efficiency in aqueous solution, since the excited state of Ln3+ can be significantly quenched by water through the excitation of the O-H vibrations. Herein, we present a simple and environmentally friendly strategy to prepare strongly red-light-emitting lanthanide complex-based luminescent materials by loading 2-thenoyltrifluoroacetate (TTA) on the Eu3+-exchanged nanoclay (Eu3+(TTAn)-NC, NC = nanoclay) and coadsorption of choline chloride (ChCl) or acetylcholine chloride (AChCl) in water. The coadsorbed molecules remarkably boosted the luminescence of Eu3+(TTAn)-NC, which is tentatively ascribed to the removal of waters coordinated in the Eu3+ coordination sphere via the complete coordination of TTA mediated by ChCl or AChCl. Highly luminescent films were facilely prepared by mixing a Eu3+(TTAn)-NC aqueous solution with PVA-ChCl (PVA-AChCl) deep eutectic solvents. This work provides a simple and environmentally friendly way for preparing highly luminescent emitting luminescent materials in aqueous solution.

Fluorescence turn-on mode of Eu3+ complex nanocomposite to detect histamine for seafood freshness

Biogenic amines (BAs), which naturally occur as chemicals in seafood, are indicators of food freshness and quality. High concentrations of BAs can cause an undesirable inflammatory response. However, traditional detection methods cannot meet the needs of rapid analysis nowadays. It is essential to explore a simple and valid method to monitor the food quality. Herein, we design and prepare a nanoclay-based turn on fluorescent material with BAs response, which could be used for the real-time and visual detection of raw fish freshness. As the concentration of BAs increase, the sensor of the fluorescence signal is significantly enhanced. The sensor demonstrated wonderful response and sensitivity which showed a detection limit of 0.935 mg/L for typical BAs histamine within a linear range of 2-14 mg/L in an aqueous solution. More importantly, we developed a responsive BAs device by doping the sensor into polyvinyl alcohol (PVA), which is well applied as a rapid-responsive fluorescent marker for visual monitoring the freshness of raw fish.

Design of a new method for one-pot synthesis of 2-amino thiazoles using trichloroisocyanuric acid in the presence of a novel multi-functional and magnetically catalytic nanosystem: Ca/4-MePy-IL@ZY-Fe3O4

In this study, an effective approach was developed to synthesize a novel, multifunctional ionic liquid nanocatalyst based on zeolite-Y with 4-methylpyridinium chloride (4-MePy-Cl) and calcium ions (Ca/4-MePy-IL@ZY). Then, Fe₃O₄ nanoparticles were produced inside the zeolite pores with the use of ultrasonic waves. XRD, FESEM, FT-IR, EDX-Map, TGA-DTA, VSM, BET, and atomic absorption techniques were used to identify the structure of the magnetic nanocomposite. Then, its catalytic activity in the one-pot synthesis of 2-aminothiazoles using trichloroisocyanuric acid (TCCA) as a green supplier of halogen ions for intermediates was studied. To provide ideal conditions for the preparation of pure products, first, the one-pot reaction of acetophenone and thiourea in various solvents, different temperatures, and the presence of different amounts of nanocatalysts and the molar amount of TCCA was used. Next, the reaction was investigated in the one-pot preparation of 2-aminothiazole derivatives under optimal conditions. This method replaces iodine (I₂), a toxic reagent, for the first time with TCCA, a safe and sustainable source of halogen. The use of non-toxic solvent and a cheap, safe, recyclable nanocatalyst, quick reaction times, high efficiency, and ease of nanocatalyst separation with the aid of a magnet are additional benefits of this method. This has led to this procedure being classified as "green chemistry".

Enhanced fluorescence quenching for p-nitrophenol in imidazolium ionic liquids using a europium-based fluorescent probe

p-Nitrophenol (PNP) is a toxic contaminant in water, the detection of which has attracted considerable attention. Since ionic liquids (ILs) have been widely used as popular solvents in both extraction and catalysts for PNP, the remediation of PNP is not limited to water and traditional organic solvents. Thus, it is significant to develop approaches for the detection of PNP in ILs. Accordingly, the present work is focused on the detection of PNP in a series of imidazolium-based ILs, 1-hexyl-3-methyl-imidazolium bromide ([Hmim]Br), 1-butyl-3-methyl-imidazolium tetrafluoroborate ([Bmim]BF₄), 1-butyl-3-methyl-imidazolium trifluoromesulfonate ([Bmim]TfO), 1-butyl-3-methyl-imidazolium trifluoroacetate ([Bmim]TA), and 1-butyl-3-methyl-imidazolium nitrate ([Bmim]NO₃), using a europium-based fluorescent probe, Na₃[Eu(DPA)₃] (DPA = 2, 6-pyridinedicarboxylic acid). This fluorescent probe showed excellent selectivity and sensitivity toward [Bmim]NO₃ in aqueous solution. Further studies showed that not only the fluorescence performance of the europium complex was enhanced in the other four ILs compared with that in water, but also the detecting capability for PNP was improved. The order of the quenching efficiency in different solvents was: [Bmim]BF₄ > [Bmim]TfO > [Hmim]Br > [Bmim]TA > water. The higher sensitivity for PNP in ILs was proven to be related to the efficient energy transfer of the europium complex and lower solvent polarity of the ILs. The quenching mechanism for the detection of PNP was established as being due to the ground state electrostatic interactions between the fluorescent probe and analyte, photoinduced electron transfer (PET) and inner filter effect (IFE).

The chemosensing of p-nitrophenol has been carried out in different solvents using a europium-based fluorescent probe and enhanced quenching efficiency was obtained in imidazolium ionic liquids compared to in water.

Highly Stretchable and Fast Self-Healing Luminescent Materials

Nowadays, the flourishing exploitation of multifunction luminescent materials with fast self-healing and superior mechanical features greatly broadens the scope for wide applications in optical and display devices, but this is still a formidably challenging task. Herein, we realize color-tunable luminescent materials functionalized with lanthanide ions (Ln³⁺) and terpyridine ligand coordination complexes that show highly stretchable and rapid self-healing performance, simultaneously broadening their application prospects both optically and mechanically. The multiple color emission, including visible and near-infrared luminescence, can be achieved by energy transfer from the coordinating terpyridine unit to Ln³⁺ via the so-called "antenna effect". The dynamic Ln-N coordination exhibits extreme stretchability and fast self-healing under ambient conditions. Of particular interest is that the healing process is not significantly affected by surface aging and atmospheric moisture. The multifunction materials open up a new pathway for future development of the next-generation wearable electronics including flexible and self-healable conductors.

A large-area luminescent downshifting layer containing an Eu3+ complex for crystalline silicon solar cells

We present a large-area luminescent down-shifting layer consists of polyvinyl alcohol embedding a newly synthesized ternary Eu³⁺ complex. C-Si solar cell coated with this layer displayed an enhancement of ~15% in external quantum efficiency.

Ammonia-Responsive Luminescence of Ln3+-β-diketonate Complex Encapsulated within Zeolite Y

Assembling Ln³⁺(HPBA_n) (Ln = Eu or Tb, HPBA = N-(2-pyridinyl)benzoylacetamide) in the cavities of zeolite Y (ZY) via the “ship-in-a-bottle” strategy leads to the formation of novel luminescent composite, Ln(HPBA_n)@ZY, whose luminescence can be easily modulated by ammonia on the basis of the energy level variation of HPBA after deprotonation process. Additionally the bimetallic complex doping sample, Eu_0.5Tb_0.5(HPBA_n)@ZY, show great potential as self-referencing luminescent sensor for detecting low ammonia concentration of 10⁻¹²–0.25 wt%.

A self-calibrated luminescent thermometer based on nanodiamond-Eu/Tb hybrid materials

ND-PMA-RE was synthesized and the ND-PMA-Eu/Tb could be served as a self-referencing luminescent thermometer due to the temperature-dependent luminescence performance.

Ion-Exchangeable Microporous Polyoxometalate Compounds with Off-Center Dopants Exhibiting Unconventional Luminescence

The synthesis of luminescent polyoxometalates (POMs) typically relies on the assembly of POM ligands with rare earth or transition metals, placing significant constraints on the composition, structure, and hence the luminescence properties of the resultant systems. Herein, we show that the ion-exchange strategy can be used for the synthesis of novel POM-based luminescent materials. We demonstrate that introducing bismuth ions into an ion-exchangeable, microporous POM compound yields an unconventional system luminescing in the near-infrared region. Experimental characterization, coupled with quantum chemical calculations, confirms that bismuth ions site-specifically occupy an off-center site in the lattice, and have an asymmetric coordination geometry unattainable by other means, thus giving rise to peculiar emission. Our findings offer an effective strategy for the synthesis of POM-based luminescent materials, and the design concept may potentially be adapted to the creation of POM-based systems with other functionalities.

Stable photoluminescence of lanthanide complexes in aqueous media through Metal-Organic Frameworks Nanoparticles with plugged surface

The photoluminescence stability of lanthanide complex in aqueous media is a prerequisite for diagnostics probes. The combination of building blocks working in concert to facilitate host-guest structures is now considered state of the art in surpassing this roadblock, yet there still remains a tremendous challenge. Here, a stable, highly-luminescent system was developed through trapping anionic complexes sensitized by tridentate pyridine-tetrazolate (pytz) ligands within the rigid framework of ZIF-8 (zeolitic imidazolate framework-8) particles (∼60 nm in size). The key to maintaining the stable luminescence of lanthanide complexes inside ZIF-8 frameworks is a stopcock design, i.e. stopper molecules (an imidazolium based ionic liquid) selectively plugged on the pore entrances located at the exterior surface of the ZIF-8 host, which protect both the host and the guests from deteriorations by surrounding ions/water molecules. Remarkably, the obtained Ln complex encapsulated ZIF-8 particles (Ln = terbium, europium) particles possessed high quantum yields (23.2% and 8.5%), large absorption cross-section (∼10^-12 cm²), and long luminescence lifetimes (1.9 and 3.0 ms) in PBS buffer. In addition, the system can realize single/multi-color encoding by altering the loading amounts and the weight ratios of complexes emitting at different wavelengths.

Flexible and transparent films consisting of lanthanide complexes for ratiometric luminescence thermometry

Herein, a flexible and transparent film consisting Eu³⁺/Tb³⁺ lanthanide complexes and poly(methylmethacrylate) was constructed via solution casting method, and further developed as a ratiometric luminescent thermometer with an excellent linear response to temperature variation from 77 to 297 K. The thermometer displays higher photo- and thermostability than corresponding pure complexs. Based on that the emission intensity ratio of ⁵D₄ → ⁷F₅ transition (Tb³⁺) to ⁵D₀ → ⁷F₂ transition (Eu³⁺) can be linearly related to the temperature, the resulting thermometer is not only more reliable than single Eu³⁺(or Tb³⁺) material based on one emission, and but also has higher sensitivity than other types of luminescent thermometers. This work highlights the practical applications of luminescent films in temperature-sensing fields.

Porous organic polymers based on melamine and 5,5′-bis(bromomethyl)-2,2′-bipyridine: functionalization with lanthanide ions for chemical sensing and highly efficient adsorption of methyl orange

Microporous POP-1 displays extremely fast adsorption of MO dyes. Moreover, Eu³⁺@POP-1 for chemical sensing can be easily prepared by a postsynthetic method.

Microwave Hydrothermal Synthesis of Terbium Ions Complexed with Porous Graphene for Effective Absorbent for Organic Dye

A luminescent terbium ions/reduced graphene oxide complex (Tb-RGO) was successfully and rapidly synthesized by the microwave hydrothermal reaction via the interactions between terbium ions and the active oxygen functional groups of graphene oxide. The as-prepared material was porous stacked by multilayer graphene in all directions. Thus, the resulting product owed the high specific surface area, high adsorption capacity and ultra-fast adsorption rate. Combined with the characteristic photoluminescence derived from terbium ions, the material has potential applications in biosensing and environmental protection.

Photochemistry and Photophysics in Silica-Based Materials: Ultrafast and Single Molecule Spectroscopy Observation

Silica-based materials (SBMs) are widely used in catalysis, photonics, and drug delivery. Their pores and cavities act as hosts of diverse guests ranging from classical dyes to drugs and quantum dots, allowing changes in the photochemical behavior of the confined guests. The heterogeneity of the guest populations as well as the confinement provided by these hosts affect the behavior of the formed hybrid materials. As a consequence, the observed reaction dynamics becomes significantly different and complex. Studying their photobehavior requires advanced laser-based spectroscopy and microscopy techniques as well as computational methods. Thanks to the development of ultrafast (spectroscopy and imaging) tools, we are witnessing an increasing interest of the scientific community to explore the intimate photobehavior of these composites. Here, we review the recent theoretical and ultrafast experimental studies of their photodynamics and discuss the results in comparison to those in homogeneous media. The discussion of the confined dynamics includes solvation and intra- and intermolecular proton-, electron-, and energy transfer events of the guest within the SBMs. Several examples of applications in photocatalysis, (photo)sensors, photonics, photovoltaics, and drug delivery demonstrate the vast potential of the SBMs in modern science and technology.

"Rigid" Luminescent Soft Materials: Europium-Containing Lyotropic Liquid Crystals Based on Polyoxyethylene Phytosterols and Ionic Liquids

Soft materials of europium β-diketonate complexes constructed in lyotropic liquid crystals (LLCs) mediated by ionic liquids (ILs) are impressive for their excellent luminescence performance and stability. For the aim to further improve their mechanical processability and luminescent tunablility, the polyoxyethylene phytosterols (BPS-n) were introduced here as structure directing agents to prepare relatively "rigid" lamellar luminescent LLCs in 1-butyl-3-methyl-imidazolium hexafluorophosphate by doping europium β-diketonate complexes with different imidazolium counterions. As a result of the solvophobic sterol ring structure of BPS-n, the more effective isolation and confinement effects of europium complexes could be achieved. The longest fluorescence lifetime and the highest quantum efficiency reported so far for europium containing lyotropic organized soft materials were thus obtained. Changing the molecular structures of BPS-n with different oxyethylene chains or doped complexes with imidazolium counterions of different alkyl chain lengths, the spacings of lamellar LLC matrixes and position of dispersed complexes became tunable. The measured luminescent and rheological properties for such composite LLCs showed a dependence on the rigidity and isolation capability afforded by sterol molecules. It was also found that the increase of counterion alkyl chain length would weaken the LLC matrix's confinement and isolation effects and therefore exhibit the deteriorated luminescence performance. The enhanced luminescence efficiency and stability of doped BPS-n LLCs reflected the excellent segregation of europium complexes from each other and therefore the reduced self-quenching process. The obtained results here present the designability of LLC matrixes and their great potential to promote achieving the luminescence tunability of soft materials.

Luminescent Lanthanide-Based Organic/Inorganic Hybrid Materials for Discrimination of Glutathione in Solution and within Hydrogels

Glutathione (GSH) as a biothiol is an essential peptide related to various diseases. Although multiple strategies for biothiols detection have been developed, there is increasing demand for sensors that can differentiate GSH from cysteine (Cys) and homocysteine (Hcy), owing to the similar structures and thiol groups in these amino acids. Herein, we report a novel Eu³⁺/LAPONITE (Lap)-based organic/inorganic hybrid material for selective detection of GSH via an "off-on" process. The fluorescence of Eu(DPA)₃@Lap-Tris can be quenched by Cu²⁺ through photoinduced electron transfer (PET). The addition of GSH into the Eu(DPA)₃@Lap-Tris/Cu²⁺ system induces the removal of Cu²⁺ from Eu(DPA)₃@Lap-Tris and blocks PET, resulting in the recovery of fluorescence. This proposed assay demonstrates higher selectivity toward GSH than Cys and Hcy, and showed a detection limit of 162 nM within a linear range of 0.5-30 μM. Unlike other GSH selective sensors, this platform could be formed into a hydrogel while its sensitivity was maintained. The sensitive response to GSH in serum samples makes this platform an efficient tool for biological applications because of its ease of preparation, high selectivity, good biocompatibility, and low toxicity.

Thermally Stable White Emitting Eu3+ Complex@Nanozeolite@Luminescent Glass Composite with High CRI for Organic-Resin-Free Warm White LEDs

Nowadays, it is still a great challenge for lanthanide complexes to be applied in solid state lighting, especially for high-power LEDs because they will suffer severe thermal-induced luminescence quenching and transmittance loss when LEDs are operated at high current. In this paper, we have not only obtained high efficient and thermally chemical stable red emitting hybrid material by introducing europium complex into nanozeolite (NZ) functionalized with the imidazolium-based stopper but also abated its thermal-induced transmittance loss and luminescence quenching behavior via coating it onto a heat-resistant luminescent glass (LG) with high thermal conductivity (1.07 W/mK). The results show that the intensity at 400 K for Eu(PPO)_n-C₄Si@NZ@LG remains 21.48% of the initial intensity at 300 K, which is virtually 153 and 13 times the intensity of Eu(PPO)₃·2H₂O and Eu(PPO)_n-C₄Si@NZ, respectively. Moreover, an organic-resin-free warm white LEDs device with a low CCT of 3994K, a high Ra of 90.2 and R9 of 57.9 was successfully fabricated simply by combining NUV-Chip-On-Board with a warm white emitting glass-film composite (i.e., yellowish-green emitting luminescent glass coated with red emitting hybrid film). Our method and results provide a feasible and promising way for lanthanide complexes to be used for general illumination in the future.

Entropy in multiple equilibria, theory and applications

Entropy controls the dependence of the equilibrium constants in the synthesis of host–guest composites on the occupation rc for channels of different length.

Luminescent hybrid composites based on the intercalation of Eu(iii) complexes into α-zirconium phosphate nanoplatelets: preparation, characterization and amine sensing

A direct ion-exchange approach was adopted to intercalate ionic lanthanide complexes into layered α-zirconium phosphate.

Europium (III) Organic Complexes in Porous Boron Nitride Microfibers: Efficient Hybrid Luminescent Material

We report the design and synthesis of a novel kind of organic-inorganic hybrid material via the incorporation of europium (III) β-diketonate complexes (Eu(TTA)₃, TTA = 2-thenoyltrifluoroacetone) into one-dimensional (1D) porous boron nitride (BN) microfibers. The developed Eu(TTA)₃@BN hybrid composites with typical 1D fibrous morphology exhibit bright visible red-light emission on UV illumination. The confinement of Eu(TTA)₃ within pores of BN microfibers not only decreases the aggregation-caused quenching in solid Eu(TTA)₃, but also improves their thermal stabilities. Moreover, The strong interactions between Eu(TTA)₃ and porous BN matrix result in an interesting energy transfer process from BN host to TTA ligand and TTA ligand to Eu³⁺ ions, leading to the remarkable increase of red emission. The synthetic approach should be a very promising strategy which can be easily expanded to other hybrid luminescent materials based on porous BN.

One-dimensional self-assembly of perylene-diimide dyes by unidirectional transit of zeolite channel openings

Confined supramolecular architectures of chromophores are key components in artificial antenna composites for solar energy harvesting and storage. A typical fabrication process, based on the insertion of dye molecules into zeolite channels, is still unknown at the molecular level. We show that slipping of perylene diimide dyes into the one-dimensional channels of zeolite L and travelling inside is only possible because of steric-interaction-induced cooperative vibrational modes of the host and the guest. The funnel-like structure of the channel opening, larger at the entrance, along with a directionally asymmetric entrance-exit probability, ensures a favorable self-assembly process of the perylene units.

Carboxyl-Functionalized Ionic Liquid Assisted Preparation of Flexible, Transparent, and Luminescent Chitosan Films as Vapor Luminescent Sensor

Herein we present a novel method to synthesize flexible self-standing films consisting of europium(III) complexes in nanoclay and chitosan, which are transparent and luminescent. Preparation takes place under aqueous conditions assisted by a carboxyl-functionalized ionic liquid (IL). The latter is used not only as a replacement for acetic acid to dissolve chitosan but, surprisingly, also to enhance the luminescence efficiency of the final films. A brighter luminescence is observed for the films prepared assisted with the ionic liquids compared to those by using acetic acid. The reason is that the ionic liquid used to dissolve chitosan can decrease proton strength on embedded platelets primarily through ion-exchange process and thus can increase the coordination number of europium(III) complexes. Exposure of the films to Et3N vapors can cause a further remarkable luminescence enhancement, while significant luminescence quenching occurred upon exposure to HCl vapors. The films are promising for applications in areas such as optoelectronics and vapor-sensitive luminescent sensors.

Highly luminescent and stable lyotropic liquid crystals based on a europium β-diketonate complex bridged by an ethylammonium cation

A europium β-diketonate complex supported by ethylammonium cations was confined within lyotropic liquid crystals with diverse mesophases, which exhibits extraordinary luminescence properties and photostabilities.

Europium(III)-β-diketonate complex-containing nanohybrid luminescent pH detector

In this work, by loading an Eu(3+)-β-diketonate complex into LAPONITE®, we report an organic-inorganic hybrid pH detection system Eu(3+)(TTA)n@Lap that is valid under acid conditions, which can serve as highly robust, reliable, rapid responsive and sensitive fluorescent pH detector. In addition, this hybrid pH detector can be easily recovered and reused by simply treating with Et3N vapor.

Luminescent europium(III)-β-diketonate complexes hosted in nanozeolite L as turn-on sensors for detecting basic molecules

The luminescence efficiency of Eu(3+)-β-diketonate complexes entrapped within the channels of nanozeolite L is severely decreased by the acidic environment in the channels. The neutralization of the acid sites can remarkably increase the luminescence efficiency due to the formation of complexes with high coordination numbers. Herein we report a simple, effective and robust luminescent sensor for detecting basic molecules (such as amines) based on the above observations.

Crystalline capsules: metal-organic frameworks locked by size-matching ligand bolts

Metal-organic frameworks (MOFs) are shown to be good examples of a new class of crystalline porous materials for guest encapsulation. Since the encapsulation/release of guest molecules in MOF hosts is a reversible process in nature, how to prevent the leaching of guests from the open pores with minimal and nondestructive modifications of the structure is a critical issue. To address this issue, we herein propose a novel strategy of encapsulating guests by introducing size-matching organic ligands as bolts to lock the pores of the MOFs through deliberately anchoring onto the open metal sites in the pores. Our proposed strategy provides a mechanical way to prevent the leaching of guests and thereby has less dependence on the specific chemical environment of the hosts, thus making it applicable for a wide variety of existing MOFs once the size-matching ligands are employed.

Luminescence enhancement after adding organic salts to nanohybrid under aqueous condition

Lanthanide-based organic-inorganic hybrid materials (LnOIH) are of immense importance for various applications nowadays, while it still remains a significant challenge to achieve high luminescence efficiency in aqueous environment. Herein we present a simple and environmentally friendly two-step strategy to prepare strongly red-light emitting nano-LnOIH by first in situ forming Eu(3+)-β-dikeonate complexes on Laponite platelets and subsequently increasing the coordination number of the complexes via the modification with a silane-functionalized imidazolium salt, which can fully protect Eu(3+) ions from the water molecule quenching. The mechanism of how the imidazolium salt favors the formation of Eu(3+)-β-dikeonate complex with large coordination number was elucidated. The result is that the removal of the abundant protons on the Laponite platelets through a mechanism of synergic effect of ion exchange and neutralization drives the formation of Eu(3+)-β-diketonate complexes with high coordination number. The high efficiency of the resulting luminescent nano-LnOIH in water endows the nanohybrid with good aqueous solution processability and opens the possibility of using them under complicated aqueous conditions for biorelated applications.