Excellent Water Dispersibility Research Articles

Structural reconstruction synthesis of highly luminous water-stable CsPbBr3@CsPb2Br5@DSPE core-shell perovskite nanocrystals for bioimaging, pattering, and LEDs

Lead halide perovskite (LHP) nanocrystals (NCs) suffer from poor stability against environmental factors (heat, moisture, oxygen, etc.), which seriously hinders their practical application. Constructing a core-shell structure could be an effective approach to improve the stability and optical properties of the LHP NCs. Herein, a novel strategy of water-triggered phase transformation and phospholipid (DSPE) micelle encapsulation is proposed, generating highly luminescent water-dispersed CsPbBr3@CsPb2Br5@DSPE core-shell-shell nanocrystals. The epitaxial growth of the CsPb2Br5 shell is induced by the in-situ reconstruction of the CsPbBr3 surface by water erosion, and the lattice mismatch with the CsPbBr3 core is small (3.8%). The further amphipathic phospholipid encapsulation guarantees their excellent water dispersity and stability. Revealed by the femtosecond transient absorption spectroscopy, the dense CsPb2Br5@DSPE shell effectively passivates the surface of the CsPbBr3 core, thus improving its stability and luminescence performance. The resulting CsPbBr3@CsPb2Br5@DSPE nanoparticles exhibit excellent performance as fluorescent probes for bioimaging, aqueous inks for high-resolution pattering, and light conversion layers for LEDs, demonstrating their promising potential in multiple applications.

Green and energy-saving tread rubber by constructing chemical cross-linking interface between graphene oxide and natural rubber

The dispersibility of fillers and interfacial interaction are crucial for polymer nanocomposites. Developing a simple, efficient and green method to simultaneously reduce and functionalize graphene oxide (GO) for preparing graphene/rubber composites with excellent dispersibility and enhanced interfacial interactions remains one of the main trends in developing and expanding the application of graphene in the rubber industry. In this work, VOC (volatile organic compound) -free and environmentally friendly L-methionine (L-Met) was selected as the functional modifier of GO. Then, L-Met-modified GO (MGO) was blended with natural rubber (NR) in an aqueous phase to prepare MGO/NR composites. The amphiphilic property of L-Met not only reduced GO but also endowed it with less agglomeration and excellent water dispersibility, which was a prerequisite for achieving uniform dispersion of GO in the NR matrix. In addition, the amino acids on the surface of MGO enhanced the compatibility between GO and the protein-phospholipid layer on the outer layer of NR latex particles. Meanwhile, L-Met containing sulfur bonds promoted rubber vulcanization, resulting in the formation of a cross-linked network between the modified GO and NR molecular chains. Compared to unmodified GO/NR composites, MGO/NR composites exhibited excellent mechanical properties and low heat build-up. More importantly, the solid tire prepared by using L-Met as the interface modifier for GO filled rubber showed lower rolling resistance and temperature rise, and the energy saving efficiency was improved. This strategy is expected to provide a new insight into the green production of organically modified graphene and the preparation of low-energy-consumption green graphene tires.

Structure-property relationship between different molecular precursors and the final properties of carbon dots: Preparation, characterization and applications as sensors for metal ions

Carbon dots (CDs) have attracted significant attention in recent years due to their interesting properties, such as photoluminescence, biocompatibility, excellent water dispersibility, as well as their potential applications in different fields. Despite these features, the complexity of their photoluminescent properties remains a subject of ongoing research and still presents unresolved questions. In this work, we investigated the preparation of various CDs from different low molecular mass starting materials containing carbon, nitrogen and/or sulfur, using hydrothermal carbonization as the preparation method. The CDs were characterized using various techniques, including TEM, FTIR, photoluminescence, UV–Vis, Raman and XPS. A detailed analysis of the initial reactions between the precursors was conducted, and our main results suggest that the optical properties of the CDs are related to fluorophores formed during the initial Michael condensation reactions between the precursors. This process produces molecular fluorescence, which plays a pivotal role in the photoluminescence properties of the nanoparticles. In addition, two of the obtained CDs were used as selective and sensitive probes for metal ions, achieving a detection limit of 0.58 μM and 0.55 μM. Finally, the findings described here can guide future works in fine-tuning the design of CDs with desired properties and different potential applications.

Magnetic polyacrylamide-based gel with tunable structure and properties and its significance in conformance control of oil reservoirs

The polyacrylamide-based gel used for oilfield conformance control exhibits poor temperature and salt resistance. This paper proposes the use of inorganic-organic core-shell materials as chemical crosslinkers for the polyacrylamide-polyethyleneimine (PAM-PEI) gel system to regulate and design its gel structure, enabling it to withstand harsh reservoir conditions. To achieve this, Fe3O4@PEI nanoparticles were prepared using a facile one-pot method and employed as chemical crosslinkers for the PAM-PEI gel. Herein, the Fe3O4 "core" provides strong stability derived from the inorganic material, and the PEI "shell" reacts with the PAM molecular chain in a transamidation reaction, so that the Fe3O4@PEI nanoparticles are riveted inside the gel by chemical crosslinking, which greatly enhances the gel structure. The Fe3O4@PEI nanoparticles exhibit a nearly spherical shape with an average diameter of approximately 75.6 nm and demonstrate excellent dispersion in water, possessing a zeta potential of 40.8 mV. In comparison to the control PAM-PEI gel, the PAM-PEI-Fe3O4@PEI gel exhibited significantly enhanced gel strength, rheological properties, long-term thermal stability, and anti-salt properties. It demonstrated a tan(δ) value of 0.12, indicative of its behavior as a nearly robust gel. Even after 360 days of placement at 90 °C in a 20 g/L NaCl solution, the gel maintained its Sydansk code at code I. Moreover, NaCl was observed to act as a retarder for this gel, while its Sydansk strength remained unaffected. In addition, the PAM-PEI-Fe3O4@PEI gel is magnetically responsive, so it can be utilized with a magnet generator to enhance its plugging performance and control its directional movement. By monitoring the magnetization rate of the gel in the reservoir, high permeability layers can be accurately identified, thus providing important practical applications in reservoir management.

Development of ZrO(OH)2@HCS co-modified molecularly imprinted gel-based electrochemical sensing platform for sensitive and selective detection of tert-butylhydroquinone in foods

Herein, a novel molecularly imprinted gel (MIG)-based electrochemical sensor equipped with hydrated zirconium oxide@hollow carbon spheres (ZrO(OH)2@HCS) was developed for highly sensitive and selective detection of tert-butylhydroquinone (TBHQ) in foods. The MIG was synthesized by using L-histidine to rapidly cross-link cationic guar gum, acrylamide and TBHQ through intermolecular hydrogen bonds and electrostatic interactions at room temperature, which offered outstanding specific recognition performance for TBHQ. ZrO(OH)2@HCS possessing excellent conductivity and water dispersibility was employed for signal amplification. Under optimal conditions, the MIG-ZrO(OH)2@HCS/GCE sensor showed a wide dynamic detection range (0.025–100 μM) with a low limit of detection (6.7 nM). TBHQ recovery experiments were conducted in spiked peanut oil and milk powder, yielding excellent recoveries. Moreover, the sensor was successfully utilized to detect TBHQ levels in snowflake chicken cutlets, crispy fried pork and boneless chicken fillets, and the results were in agreement with those obtained by the high performance liquid chromatography method.

Comparative Study of Electrochromic Supercapacitor Electrodes Based on PEDOT:PSS/ITO Fabricated via Spray and Electrospray Methods.

PSS stands out as a leading commercial conducting polymer due to its excellent water dispersibility, controllable miscibility, adjustable conductivity, and ability to form films through various techniques. This study investigates the electrochemical and electrochromic performance of electrodes prepared by depositing PEDOT:PSS onto ITO surfaces by using two distinct methods: conventional spray coating and electrospray deposition. Detailed characterization of the prepared electrodes was performed by using atomic force microscopy, scanning electron microscopy, Fourier-transform infrared, and Raman spectroscopy techniques. Our findings reveal that electrodes fabricated via electrospray deposition (PEDOT:PSS/ITO electrode_2) significantly outperform those made by spray coating (PEDOT:PSS/ITO electrode_1). Specifically, electrode_2 exhibits a capacitance of 1678.60 μF cm-2, compared to 826.14 μF cm-2 for electrode_1, at a current density of 10 μA cm-2. PSS electrodes exhibit areal energy densities of 0.41 and 0.84 mW h cm-2, along with power densities of 4.96 and 4.97 μW cm-2, respectively. Moreover, electrode_2 demonstrates a high coloration efficiency of 84.32 cm2 C-1 and fast response times of 1.36 s for coloration and 0.98 s for bleaching. This study highlights the advantages of electrospray deposition over traditional methods, showcasing the potential of electrospray-prepared PEDOT:PSS electrodes for use in multifunctional energy storage devices.

Natural and polyanionic heparin polysaccharide functionalized upconversion nanoparticles for highly sensitive and selective ratiometric detection of pesticide

Pesticide contamination is a global concern, threatening human health and food safety. Herein, we developed heparin (HEP) functionalized upconversion nanoparticles (UCNPs)-based ratiometric nanosensor for the sensitive detection of 2,6-dichloro-4-nitroaniline (DCN) pesticide via inner filter effect. The strategy for HEP functionalization of UCNPs is based on adjusting the surface potentials of UCNPs with polyanionic HEP through the electrostatic interaction. UCNPs (NaYbF4:Gd/Y/Tm@NaYbF4@NaYF4) was designed with core-shell-shell structure and extra sensitizer layer for efficient and strong upconversion luminescence (UCL) in the range of UV to NIR. After incorporation of DCN, the upconverted UV emission of UCNPs-HEP ratiometric nanosensor was considerably quenched with the NIR UCL at 800 nm remaining unchanged as internal standard. The UCNPs-HEP ratiometric nanosensor can achieve outstandingly selective and sensitive detection of DCN at the wide linear range of 5–300 μM with a detection limit of 0.41 μM. The remarkable applicability of the UCNPs-HEP ratiometric nanosensor was verified in apple, cucumber and grapes samples. The developed UCNPs-HEP ratiometric nanosensor with excellent biocompatibility and water dispersion capability, is promising for convenient, selective and sensitive sensing of DCN towards food and aqueous samples.

Penetrative Ionic Organic Molecular Cage Nanozyme for the Targeted Treatment of Keratomycosis.

Keratomycosis, caused by pathogenic fungi, is an intractable blinding eye disease. Corneal penetration is an essential requirement for conventional antifungal medications to address keratomycosis. Due to the distinctive anatomical and physiological structure of the cornea, the therapeutic efficacy is hampered by the inadequate penetration capacity. Despite the emergence of diverse antifungal drug delivery systems and advanced antifungal nanomaterials, it has remained challenging to achieve corneal penetration over the past decade. This study fabricates a penetrative ionic organic molecular cage-based nanozyme (OMCzyme) for treating keratomycosis. The synthesis of OMCzyme involved two steps. Initially, the ionic OMC is synthesized by a [2+3] cycloimination reaction of triformylphloroglucinol and 2,3-diaminopropionic acid. Subsequently, OMCzyme is fabricated by coordination of Fe2⁺ with carboxyl anions and phenolic hydroxyls in the organic cage, and further deposition of silver nanoparticles on the surface of OMC-Fe complex. The as-prepared OMCzyme demonstrates excellent water dispersion, peroxidase-like activity, in vitro and in vivo biocompatibility, and corneal penetration. Notably, the nanozyme displays targeted antifungal activity, effectively combating Fusarium solani with negligible cytotoxicity toward human corneal epithelial cells. The hybrid mimic is further demonstrated to be effective in treating keratomycosis in mice, indicating the potential of OMCzyme for curing fungal infectious diseases.

Nitrogen-doped carbon dots as fluorescent probes for sensitive and selective determination of Fe3+

At present, the contamination of water resources by heavy metal ions has posed a significant threat to human survival. Therefore, it is particularly critical to develop low-cost, easy-to-use, and highly efficient heavy metal detection technologies. In this work, a fast and cost-effective fluorescent probe for nitrogen-doped carbon dots (N-CDs) was prepared using one-step hydrothermal method with citric acid (CA) as carbon source, and melamine as nitrogen source. The structural and optical characterizations of the resulting N-CDs were investigated in details. The results showed that the quantum yield of the prepared fluorescent probe was as high as 45 %, and an average fluorescence lifetime was about 7.80 ns. N-CDs have excellent water solubility and dispersibility, with an average size of 2.58 nm. N-CDs exhibited excellent specific responsiveness to Fe3+ and can be used as an effective method for detecting Fe3+ at low-concentrations (the concentrations of N-CDs as low as 0.24 μg/mL) using fluorescent probes. The linear response of the fluorescent probe N-CDs to Fe3+ was formed in the concentration range of 20–80 μM, and the detection limit was 3.18 μM. In addition, in the actual water samples analysis, the recovery rate reached 97.05–100.58 %. The prepared of N-CDs provide available Fe3+ fluorescent probes in the environment.

Yeast‐Controlled Double‐Shelled CaCO3/CaF2 Hollow Nanospheres with Hierarchically Porous for Sustained pH‐Sensitive Drug Release

Comprehensive SummaryHierarchically porous materials (HP materials) are believed one of the most hopeful matrix materials because of their distinctive multimodal pore structures and tremendous application potentials in the field of biomedicine. However, green and facile synthesis of hierarchically porous nanomaterials with beneficial water dispersibility and biocompatibility is still a great challenge. Herein, a novel biomimetic strategy is proposed to prepare the cell‐tailored double‐shelled HPCaCO3/CaF2 hollow nanospheres under the mediation of yeast cells. The biomolecules derived from the secretion of yeast cells are used as conditioning and stabilizing agents to control the biosynthesis of the HPCaCO3/CaF2 materials, which exhibit excellent water dispersibility and favorable biocompatibility. The double‐shelled CaCO3/CaF2 nanospheres hold hierarchically porous structure and have abundant pore channel and large specific surface area, showing high drug‐loading and a prolonged drug sustainable release profile by the pore‐by‐pore diffusion pattern of the hierarchical pores. Otherwise, the HPCaCO3 with pH‐sensitivity could controllably release drug doxorubicin hydrochloride (DOX) at the acidic tumor microenvironment. Both in vitro and in vivo results demonstrate that HPCaCO3/CaF2 has the sustainable pH‐sensitive drug release property, showing an enhanced therapeutic effect. Summarily, this study provides a biomimetic strategy to synthesize the hierarchically porous double‐shelled hollow nanomaterials for applying in sustainable drug delivery system.

“Turn ON-OFF-ON” photoluminescence detection of EDTA using Moringa oleifera gum-derived carbon dots

This study offers a simplistic approach to hydrothermally synthesizing photoluminescent carbon dots (CDs) using Moringa oleifera Gum (MOG) to detect and quantify EDTA. The as-synthesized Moringa oleifera Gum-derived CDs (MOG-CDs) exhibited an average size of 3.41±0.44 nm and are amorphous. They are naturally doped with calcium and sulphur. Functional groups linked with these heteroatoms and oxygenated linkers are responsible for excellent water dispersibility, good stability, and remarkable optical properties of MOG-CDs. The MOG-CDs demonstrated a high quantum yield of 27.53%. The PL intensity of MOG-CDs was selectively quenched by the introduction of Pb2+ ions, which were further used as a passivating agent for EDTA detection, i.e., the quenched PL can be restored by the addition of EDTA into MOG-CD+Pb2+ system. This Turn “ON-OFF-ON” strategy was used to quantify EDTA with a LOD of 2.6 ppb (8.9 nM). The practicality and viability of the proposed photoluminescent probe were validated by quantifying EDTA in actual samples. The results demonstrated favourable spiked recoveries ranging from 92.59% to 108.69%, indicating a high level of accuracy. Additionally, it displayed excellent reproducibility, as suggested by relative standard deviation (RSD) <5.51%. In parallel, an "IMPLICATION" Boolean logic gate was constructed by employing the PL restoration of the MOG-CD+Pb2+ sensing probe in the presence of EDTA.

Effect of poly(styrene sulfonate) treatment on the structural evolution and sonodynamic performance of PCN-224 nanoparticles

Porphyrin based nanosize metal-organic frameworks (MOFs), such as PCN-224, are promising sonosensitizers for the sonodynamic therapy (SDT) due to their high porphyrin loading capacity and excellent water dispersity. However, the limited pore size of PCN-224 and the close proximity between porphyrins may impede the generation and diffusion of reactive oxygen species (ROS). In this study, a facile ligand exchange method is developed to regulate the structure and the content of tetrakis(carboxyphenyl)-porphyrin (TCPP) in the treated PCN-224 nanoparticles (NPs). Through simple incubation of PCN-224 NPs in poly(styrene sulfonate) (PSS) solution, the ligand exchange between PSS and TCPP happens and a part of TCPP is released to the solution. The ligand exchange results in the transformation of the crystalline structure to amorphous structure of PCN-224, the formation of larger pores and the decrease of surface area. The increased pore size can enhance the generation ability of 1O2 due to the favorable diffusion of substances. This effect can compensate the decreased amount of TCPP in the NPs until the incubation time reaches 8 h in a 2 mg/mL PSS. After balancing the two factors of structure change and TCPP content in the treated PCN-224 NPs, one can achieve their optimal SDT performance. Through a ligand exchange process, this work provides a facile method to regulate the structure of MOFs-based sonosensitizers and their SDT performance.

Investigation of the Application and Mechanism of Nitrogen and Phosphorus Co-doped Carbon Dots for Mercury Ion Detection.

In this paper, we obtained nitrogen and phosphorus co-doped carbon dots through a hydrothermal method using o-phenylenediamine and citric acid in a 40% phosphoric acid environment. The carbon dots emitted fluorescence at 476nm under excitation at 408nm and exhibited good selectivity and high sensitivity towards mercury ions. These carbon dots showed excellent dispersibility in water and maintained stable fluorescence even in high concentration salt environments. The interaction between mercury ions and functional groups on the carbon dots surface through electrostatic interaction resulted in static quenching. Simultaneously, by detecting the lifetime and transient absorption spectra of the carbon dots, we observed that the coordination of mercury ions with the carbon dots broadened the band structure of the carbon dots, and the existing photoinduced electron transfer process increased the non-radiative transition channel. The combined effect of dynamic quenching and static quenching significantly reduced the fluorescence intensity of the carbon dots at 476nm. The carbon dots exhibited linear detection of mercury ions in the range of 0.01-1 µM, with a detection limit as low as 0.0245 µM. In terms of practical water environmental detection applications, these carbon dots were able to effectively detect mercury ions in tap water and lake water, demonstrating their broad application prospects in the field of environmental metal analysis.

Ferroptosis boosted oral cancer photodynamic therapy by carrier-free Sorafenib-Ce6 self-assembly nanoparticles

Oral cancer is a disease with high morbidity and mortality worldwide and greatly impacts the quality of life, especially in patients with advanced stages. Photodynamic therapy (PDT) is one of the most effective clinical treatments for oral cancers. However, most clinically applied photosensitizers have several deficiencies, including oxygen dependence, poor aqueous solubility, and a lack of tumor-targeting ability. Herein, the carrier-free multifunctional Sorafenib (Sor), chlorin e6 (Ce6), and Fe3+ self-assembly co-delivery nanoparticles (Sor-Ce6 NPs) were constructed via combining a ferroptosis inducer Sor and a photosensitizer Ce6 for synergetic therapy. The as-synthesized Sor-Ce6 NPs presented excellent colloidal stability and water dispersity with good in vivo tumor-targeting ability. More significantly, the low dose of Sor-Ce6 NPs had little dark toxicity but produced significantly enhanced ROS and supplied O2 sustainably to increase phototoxicity through ferroptosis pathway. Notably, the Sor-Ce6 NPs showed significantly higher in vitro and in vivo anti-tumor efficacy than the Sor/Ce6 mixture due to the improvement of cellular uptake and the incorporation of foreign Fe ions in the system, which also confer the T1 magnetic resonance-guided imaging ability to the formed Sor-Ce6 NPs. Our study demonstrates a promising self-assembled strategy for overcoming hypoxia-related PDT resistance for oral cancer treatment.

Ionized water-soluble organic nanosheets with light/ultrasound dual excitation channels for efficient killing of multidrug-resistant bacteria.

A novel ionized heavy-atom-free two-dimensional organic nanosheet was prepared and exhibited highly selective generation of singlet oxygen under both light and ultrasound excitation. These ionized nanosheets displayed excellent dispersibility in water and enhanced singlet oxygen production efficiency compared to their non-assembled monomers. Antimicrobial experiments have revealed their potent bactericidal effects on drug-resistant E. coli and S. aureus under both visible light and ultrasound irradiation.

Fabrication of monodisperse micron-sized and aldehyde-functionalized microspheres coating with covalent organic framework for efficient and rapid removal of copper ions from wastewater.

Covalent organic frameworks (COFs) possess an excellent ability for absorbing heavy metals, but their uneven particle size, difficult separation, and poor dispersion limit their wide application in the treatment of heavy metal pollution. In this paper, a monodisperse poly(4-allyloxybenzaldehyde-co-divinylbenzene) microsphere (denoted as PAD) was prepared with 4-allyloxybenzaldehyde as a functional monomer and divinylbenzene (DVB) as a crosslinker by one-step seed swelling polymerization. Subsequently, oxalyldihydrazide (ODH) and 2,4,6-trihydroxybenzene-1,3,5-tricarbaldehyde (Tp) were chosen as the precursors for coating the COF layer onto the surface of PAD through a one-pot method. The resulting monodisperse particles (diameter = 6.3 μm) with a core-shell structure were assigned as PAD@COF and possessed excellent dispersibility in water along with a high specific surface area of 163.8 m2 g-1. In isothermal and dynamic adsorption experiments, the maximum adsorption capacity of Cu2+ reached 270.9 mg g-1, with the adsorption amount reaching 93 mg g-1 after only 10 min. The Langmuir isothermal adsorption model and pseudo-second-order kinetic model were consistent with the adsorption process, indicating that the adsorption of Cu2+ on PAD@COF occurred as a monolayer and that the adsorption process was controlled by chemical processes.

New features of edge-selectively hydroxylated graphene nanosheets as NIR-II photothermal agent and sonothermal agent for tumor therapy.

Second near-infrared (NIR-II) laser-mediated photothermal therapy and sonothermal therapy using low-intensity focused ultrasound exposure for tumors have attracted increasing attention owing to their ability to penetrate deep tissues and provide noninvasive ablation with high therapeutic efficacy. However, their applications were limited by the shortness of optimal NIR-II photothermal agents and sonothermal agents. In this study, we discovered that the edge-selectively hydroxylated graphene nanosheets (EHG NSs) with excellent water dispersibility and an "intact conjugated plane" were not only an outstanding NIR-II photothermal agent but also an effective sonothermal agent for tumor therapy. EHG NSs were incorporated into an injectable adhesive thermosensitive hydrogel with a characteristic sol-gel phase transition behavior. EHG NSs endowed the injectable hydrogel with an exceptional photothermal effect under the laser irradiation (1064 nm, 1.0 W cm-2) as well as an effective sonothermal effect under ultrasonic exposure (3.0 MHz, 2.1 W cm-2), effectively killing tumor cells in vitro and inhibiting tumor growth after intratumoral injection. Especially, the NIR-II photothermal therapy based on the hybrid hydrogel completely ablated the primary tumors and effectively activated systemic anti-tumor immune responses benefiting from the protein adsorption capacity of the injectable hydrogel, significantly inhibiting the growth of the distal tumors. Collectively, EHG nanosheets loaded in the injectable hydrogel will be a promising "all-rounder" for noninvasive deep penetrating thermotherapy and a potent platform that integrates various therapies.

Synthesis of a Zn-MOF fluorescent material for sensitive detection of biothiols via an inner filter effect with MnO2 nanosheets.

In this study, zinc ions were employed as the central metal, while 4,4',4''-nitrilotribenzoic acid (H3NTB) served as the fluorescent organic ligand. Through a single-step solvothermal approach, a novel Zn-based metal-organic framework (Zn-MOF) fluorescent material was successfully synthesized. The Zn-MOFs exhibit a cubic morphology, outstanding fluorescence properties, excellent water dispersibility, and robust resistance to high temperature and strong alkaline conditions. Additionally, MnO2 nanosheets (NSs) were effectively exfoliated from MnO2 particles using ultrasonic treatment. These MnO2 NSs possess a broad UV-Vis absorption band that overlaps with the fluorescence spectra of Zn-MOFs. Leveraging the inner filter effect (IFE) between MnO2 and Zn-MOFs, a Zn-MOF-based fluorescence bioassay technique was developed for the detection of biothiols. The results demonstrate that this Zn-MOF-based fluorescence detection platform exhibits a remarkable sensitivity towards biothiols, achieving a detection limit of 0.067 μM, surpassing that of other reported MnO2-based detection methods. Furthermore, this detection platform has been successfully applied to the quantitation of glutathione (GSH) in human serum, highlighting its potential for highly sensitive and specific detection of biothiols.

The influence of the polyol solvents on the continuous growth of water-dispersible iron oxide nanoparticles

Magnetic nanoparticles have continued to gain significant attention due to their unique magnetic properties and potential applications. However, it is still challenging to directly synthesize water-dispersible magnetic nanoparticles with controlled size for biomedical applications. This study investigates the influence of solvents on the continuous growth of magnetic nanoparticles, aiming to achieve controlled size and excellent water dispersibility via thermal decomposition in polyol solvents. The size of the nanoparticles gradually increases with longer polyol chain solvents. The increase in nanoparticles size is more significant under a higher reaction temperature (220 °C) compared to a lower temperature (190 °C). These monodispersed nanoparticles exhibit strong superparamagnetic properties, improving with longer solvent chain lengths at the same size. Magnetic resonance imaging (MRI) studies reveal higher relaxivities for magnetic nanoparticles synthesized in longer-chain polyols. This research offers valuable insights for synthesizing magnetic nanoparticles with precise sizes, magnetic properties, and biomedical applications.Graphical abstract

One-step synthesis of cyclodextrin-based fluorescent hyperbranched polymer as type I photosensitizer for effective photodynamic therapy

Photodynamic therapy (PDT) is a promising treatment regime for cancer therapy with some advantages such as minimal invasiveness, high spatiotemporal selectivity, and negligible drug resistance. Developing Type I photosensitizer (PS) is a viable strategy to overcome the limitations of conventional O2-dependent Type Ⅱ PS, whereas there are still significant challenges. Herein, we report the synthesis of β-cyclodextrin-based fluorescent hyperbranched polymer (β-CD-HPG-DEP) through a one-step anionic ring-opening polymerization between β-cyclodextrin (β-CD), glycidol and a fluorescent molecule DEP. The potential utilization of β-CD-HPG-DEP as the agent for cancer phototheranostics was also investigated in detail. The results demonstrated that β-CD-HPG-DEP possesses excellent water dispersibility, good biocompatibility, high reactive oxygen species (ROS) generation efficiency mainly via Type I mechanism, and extraordinary fluorescence imaging capability. Meanwhile, β-CD-HPG-DEP has great potential to serve as drug delivery vehicle since the cyclodextrin unit has many hydroxyl groups, thus providing a promising strategy for designing and fabrication of multifunctional theranostics. Considering the simple synthesis route, ready designability and multifunctional potential of anionic ring-opening polymerization, as well as good biocompatibility of resultant polymer, we believe the strategy developed in this work could also be a rational route to synthesize multifunctional composites for various biomedical applications.