Good Monodispersity Research Articles

Fluorescent carbon nanodots facilely extracted from Coca Cola for temperature sensing

A novel method for the fabrication of carbon nanodots (CDs) is introduced: extracting CDs from the well-known soft drink Coca Cola via dialysis. The obtained CDs are of good monodispersity with a narrow size distribution (average diameter of 3.0 nm), good biocompatibility, high solubility (about 180 mg ml−1) and stable fluorescence even at a high salt concentration. Furthermore, they are sensitive to the temperature change with a linear relationship between the fluorescence intensity and temperature from 5 °C–95 °C. The CDs have been applied in high stable temperature sensing. This protocol is quite simple, green, cost-effective and technologically simple, which might be used for a range of applications including sensing, catalysts, drug and gene delivery, and so on.

A Bimetallic Silver-Neodymium Theranostic Nanoparticle with Multimodal NIR/MRI/CT Imaging and Combined Chemo-photothermal Therapy.

An engineered metallic nanostructure is an excellent candidate for "theranosis" of cancer, having intrinsic properties of multimodal imaging and therapy. Toward this target, the development of silver-neodymium bimetallic nanoparticles (Ag-Nd BNPs) via microwave-assisted polyol synthesis is presented. The resultant Ag-Nd BNPs exhibit good monodispersity with average size of 10 nm, fluorescence in the near-infrared (NIR) region, and magnetic properties. The Ag-Nd BNPs also validate MRI, CT, and NIR trimodal imaging ability and enunciate valuable temperature response upon irradiation under a NIR laser. Aided by chitosan functionalization on the surface, the Ag-Nd BNPs deliver good biocompatibility and also promote the loading of paclitaxel, an anticancer drug. Isothermal titration calorimetry affirms the combination of strong binding affinity of drug and high loading efficiency of 7 drug molecules per nanoparticle. Moreover, Ag-Nd BNPs also illustrate a highly efficient photothermal effect in PBS. Therefore, the synergistic effects of paclitaxel and the photothermal effect make BNPs excellent "combined therapeutic agents", and also give them the important ability to destroy cancer cells in vitro at very low dose in comparison to single therapy. Thus, the Ag-Nd BNPs unveil a combination of MRI/CT/NIR imaging and chemo-photothermal therapy that ensures accurate diagnosis at an early stage and comprehensive eradication of tumor cells without affecting healthy cells.

Publisher’s note

Lipid based nanoparticles (LBNs) with excellent biocompatibility and versatility have received much attention from the drug delivery community recently. A detailed understanding of in vitro and vivo fate of LBNs is important for developing different types of LBNs with improved selectivity and low cytotoxicity. We developed a novel near-infrared (NIR) probe with high fluorescence, designated as DSPE-ir623 (iDSPE). Then, we prepared iDSPE-embeded liposomes (iLPs) with two different hydrodynamic sizes (∼100nm and ∼400nm) to evaluate the effect of particle size on cellular uptake and biodistribution of nanoliposomes in vivo. These iLPs were proved to exhibit good monodispersity, excellent fluorescence and stability. In vitro cell uptake tests demonstrated that iLPs-1 (∼100nm) were taken up more by HT-29 cells than iLPs-2 (∼400nm). Notably, the fluorescence of iLPs can be employed for real-time monitoring of the subcellular locating and its metabolic distribution in vivo. Near-infrared imaging in vivo illustrated that iLPs-1 was mainly accumulated in the tumor tissues, while iLPs-2 was accumulated in liver and spleen. The results indicated that the size of iLPs play an important role in the regulation of intracellular trafficking and biodistribution of liposomes, which also provide a new insight into the development of more effective LBNs. Hence, iDSPE might be a promising tool for the reliable tracing of different types of LBNs.

MRI-guided targeting delivery of doxorubicin with reduction-responsive lipid-polymer hybrid nanoparticles.

In recent years, there has been increasing interest in developing a multifunctional nanoscale platform for cancer monitoring and chemotherapy. However, there is still a big challenge for current clinic contrast agents to improve their poor tumor selectivity and response. Herein, we report a new kind of Gd complex and folate-coated redox-sensitive lipid-polymer hybrid nanoparticle (Gd-FLPNP) for tumor-targeted magnetic resonance imaging and therapy. Gd-FLPNPs can simultaneously accomplish diagnostic imaging, and specific targeting and controlled release of doxorubicin (DOX). They exhibit good monodispersity, excellent size stability, and a well-defined core-shell structure. Paramagnetic nanoparticles based on gadolinium-diethylenetriaminepentaacetic acid-bis-cetylamine have paramagnetic properties with an approximately two-fold enhancement in the longitudinal relaxivity compared to clinical used Magnevist. For targeted and reduction-sensitive drug delivery, Gd-FLPNPs released DOX faster and enhanced cell uptake in vitro, and exhibited better antitumor effect both in vitro and in vivo.

Erlotinib-loaded albumin nanoparticles: A novel injectable form of erlotinib and its in vivo efficacy against pancreatic adenocarcinoma ASPC-1 and PANC-1 cell lines

Erlotinib was loaded on albumin nanoparticles for the first time and the cytotoxic effect of the resulting nanoparticles against ASPC-1 and PANC-1 pancreatic adenocarcinoma cell lines was evaluated. The carrier (albumin nanoparticles, ANPs) was synthesized by desolvation method using a mixed solvent followed by thermal crosslinking for stabilization. ANPs and the drug-loaded ANPs were characterized by field emission scanning and transmission electron microscopies, particle size analysis and Fourier transform infrared spectroscopy. The nanoformulation had a size of <14nm with a good monodispersity. Drug loading and encapsulation efficiencies were evaluated as 27 and 44%. Cytotoxicity assays after 72h revealed the potential of ANPs to improve erlotinib toxicity (54% against 34% of free drug toward ASPC-1 cell line, and 52% against 30% toward PANC-1 cell line). Values of IC50 were obtained for both cell lines and indicated significant reduction in the erlotinib dose necessary for killing the cells, while, ANPs were completely safe. The results demonstrated that erlotinib-loaded ANPs had a remarkable potential for pancreatic cancer drug delivery.

Ultrasmall Superparamagnetic Iron Oxide Nanoparticle for T2-Weighted Magnetic Resonance Imaging.

A facile method to synthesize ultrasmall-sized supermagnetic iron oxide nanoparticles with good monodispersity and high relaxivity is desired for magnetic resonance imaging (MRI) technology. Herein, we have developed a one-step method to direct the formation of superparamagnetic iron oxide nanoparticle (uBSPIO) using albumin under mild conditions. The resulting uBSPIO possess ultrasmall size (4.78 ± 0.55 nm) and super high MR relaxivity (444.56 ± 8.82 mM-1 s-1). After grafted by the luteinizing hormone release hormone peptide (LHRH), the uBSPIO could targeted and accumulated in the tumor site. Finally, the uBSPIOs had good stability and did not induce cytotoxicity in vitro or major organ toxicity in vivo. The uBSPIOs are promising contrast agents for MRI.

Extracellular biosynthesis of silver nanoparticles using the cell-free filtrate of nematophagous fungus Duddingtonia flagrans.

The biosynthesis of metallic nanoparticles (NPs) using biological systems such as fungi has evolved to become an important area of nanobiotechnology. Herein, we report for the first time the extracellular synthesis of highly stable silver NPs (AgNPs) using the nematophagous fungus Duddingtonia flagrans (AC001). The fungal cell-free filtrate was analyzed by the Bradford method and 3,5-dinitrosalicylic acid assay and used to synthesize the AgNPs in the presence of a 1 mM AgNO3 solution. They have been characterized by UV–Vis spectroscopy, X-ray diffraction, transmission electron microscopy, dynamic light scattering, Zeta potential measurements, Fourier-transform infrared, and Raman spectroscopes. UV–Vis spectroscopy confirmed bioreduction, while X-ray diffractometry established the crystalline nature of the AgNPs. Dynamic light scattering and transmission electron microscopy images showed approximately 11, 38 nm monodisperse and quasispherical AgNPs. Zeta potential analysis was able to show a considerable stability of AgNPs. The N–H stretches in Fourier-transform infrared spectroscopy indicate the presence of protein molecules. The Raman bands suggest that chitinase was involved in the growth and stabilization of AgNPs, through the coating of the particles. Our results show that the NPs we synthesized have good stability, high yield, and monodispersion.

One-pot green synthesis of supramolecular β-cyclodextrin functionalized gold nanoclusters and their application for highly selective and sensitive fluorescent detection of dopamine

We report here one-pot synthetic method for preparing gold nanoclusters (AuNCs) by employing pristine β-cyclodextrin (β-CD) as reducing-cum-stabilizing agent for the first time. The developed AuNCs were used as a selective and sensitive fluorescent probe for sensing dopamine (DA) based on β-CD supramolecular interaction and quenching effect. The as-synthesized β-CD protected gold nanoclusters (β-CD@AuNCs) showed good monodispersity with ultra-small size < 2.0nm and exhibited strong fluorescence intensity at 450nm β-CD@AuNCs have been systematically characterized by UV–vis absorption spectroscopy, photoluminescence spectroscopy, X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy, transmission electron microscopy and dynamic light scattering. DA can trigger significant fluorescence quenching of β-CD@AuNCs on the basis of photo-induced electron transfer (PET) mechanism. Fluorescence lifetimes characterization of β-CD@AuNCs and DA/β-CD@AuNCs conjugate were performed to confirm the proposed PET process. A good linearity range (100.0nM to 80.0μM) for DA detection was obtained by applying the Stern-Volmer equation with lower LOD (3σ/s) of 20.0nM, revealing the high sensitivity of the method. This fluorescent AuNCs sensing probe for DA demonstrates excellent selectivity among 24 biological interferents owing to the specificity of steric host-guest interactions between DA and the nanocavity of β-CD capped on AuNCs. The developed nanosensor was successfully applied in the detection of DA in human serum plasma and injection dosage forms, indicating its good practicability for DA detection in biological and pharmaceutical research.

Shape-Controlled Hollow Mesoporous Silica Nanoparticles with Multifunctional Capping for In Vitro Cancer Treatment.

A series of multifunctional shape-controlled nonspherical hollow mesoporous silica nanoparticles (HMSNs) drug carriers have been prepared by employing Fe2 O3 with four morphologies (capsule, cube, rice, and rhombus) as a sacrificial template and a multifunctional cap as the encapsulating shell. The resulting shape-controlled nonspherical HMSNs perfectly replicate the original morphology of the Fe2 O3 templates, which possess a high specific surface area, good monodispersity, perpendicular mesoporous channels, and excellent biocompatibility. After modification of polyethylene glycol (PEG) and folic acid (FA), the shape-controlled HMSN core and functional shell can then be integrated into a single device (HMSNs-PEG-FA) to provide an efficient and tumor-cell-selective drug-delivery system. The shape-controlled HMSNs and HMSNs-PEG-FA all show controlled pH-responsive release behavior for the anticancer drug doxorubicin hydrochloride (DOX). The in vitro results indicate that HMSNs-PEG-FA is biocompatible and selectively targets HeLa cells (overexpressed folate receptors). Fluorescence images show that desirable surface modification and the nonspherical shape effectively facilitate cellular internalization of HMSNs. It is expected that the construction of these unique nanomaterials with controlled morphology through the hard-templating technique may also provide useful information for the design of nanoscale multifunctional systems.

Facile synthesis of Nb2O5 nanobelts assembled from nanorods and their applications in lithium ion batteries

Hierarchical 1D Nb2O5 nanobelts are successfully synthesized via a facile solvothermal method and following thermal treatment. The as-formed Nb2O5 nanobelts are characterized by XRD, FESEM, TEM, and BET, and the results indicate that they possess pseudohexagonal structure and are composed of ultranarrow nanorods with an average diameter of ca. 15 nm. When used as anodic materials for lithium ion batteries, the obtained Nb2O5 nanobelts can deliver initial discharge capacities of 209.3 mAh g−1 at the current density of 0.5 C. In addition, the Nb2O5 nanobelts exhibit a reversible capacity of 95.8 mAh g−1 after 200 cycles at relatively high current density of 5 C. The good electrochemical performance of the Nb2O5 nanobelts may be ascribed to their good monodispersity, high specific surface areas, and narrow rod-like building blocks. The Nb2O5 nanobelts can be developed as promising anodes for high-rate 2 V LIBs with good safety.

Hierarchical MoO2/C microspheres: Preparation and application as anode materials for lithium ion batteries

Hierarchical MoO2/C microsphere has been successfully prepared via a template-assisted process in the presence of polyethylene glycol followed by thermal annealing. The as-synthesized MoO2/C microsphere with a diameter of about 1.5 μm had rough surface and good monodispersity. Notably, each microsphere consisted of many nanoparticles with a size of about 20 nm and existed abundant of porous. The MoO2/C microsphere was used as an anode material for lithium ion batteries and its electrical property was also determined in this work. At a current density of 100 mA g−1, the MoO2/C composite exhibited the discharge specific capacity of 768 mAh g−1 in the first cycle and 800 mAh g−1 after 300 cycles. Even at a high current density of 500 mA g−1, the discharge specific capacity of 565 mAh g−1 can be maintained after 300 cycles. Such high capacity and excellent cycling stability might be attributed to the hierarchical and porous structure of the MoO2/C, greatly enhancing lithium ions transport and buffering the volume change. Several advantages such as the high electrochemical performance, mild reaction conditions and structural controllability render the hierarchical MoO2/C microsphere as a potential anode material for high performance Li-ion batteries.

Self-Assembled Exopolysaccharide Nanoparticles for Bioremediation and Green Synthesis of Noble Metal Nanoparticles.

Continuing efforts have been made to explore novel exopolysaccharides (EPSs) for valuable applications. In this research, we report for the first time that a novel non-glucan EPS named EPS-605 can self-assemble to form spherical nanosize particles of ∼88 nm in diameter, expanding both the range of EPS type and structural type that EPSs self-assemble into. Characterization of EPS-605 shows that it is composed of mannose, glucose, and galactose with several modifications including acylation, phosphorylation, sulfation, and carboxylation, and a highly negative charge. EPS-605 showed a record biosorption capability for Pb2+, Cu2+, Cd2+, and methylene blue as compared to that of other reported EPSs, biosorbents, and nanosorbents. The adsorption ability of EPS-605 is affected by pH, temperature, the initial adsorbate concentration, the contact time, and the presence of background electrolytes. The mechanism of EPS-605 adsorbing heavy metals seems to be different to that for dyes. Moreover, EPS-605 can serve as the reductant in the synthesis of Au nanoparticles (AuNPs) and AgNPs enabling good monodispersity within the shortest time (of 30 min) compared to that from other EPSs and without any extra pretreatment. Our research advances the development of novel EPSs and provides a new, eco-friendly, and renewable platform for both the bioremediation and green synthesis of nanomaterials.

Effect of Ammonia on the SiO&lt;sub&gt;2&lt;/sub&gt; Colloidal Particles Synthesized by the Stöber Method

Various sizes SiO2 colloidal particles in the size range of 260-950 nm were synthesized by the stöber method by adjusting the amount of ammonia from 9.0 ml to 3.0 ml while keeping 20.0 ml tetraethyl orthosilicate (TEOS), 125.0 ml ethanol, 6.0 ml ammonia and 18.0 ml distilled water fixed. In addition, X-ray diffraction (XRD) and scanning electron microscopy (SEM) were employed to analyze the crystallinity and morphology of the synthesized SiO2 colloidal particles; the XRD result show that the SiO2 colloidal particles are amorphous at room temperature; the SEM results demonstrated that the amount of ammonia could have significant effects on the size, size distribution and sphericity of the SiO2 colloidal particles. SiO2 colloidal particles were resulted with good monodispersity when the amount of ammonia was in the range of 6.0-90 ml, while SiO2 colloidal particles with double size distribution were obtained when the range is 3.0-4.5 ml; on the other hand, SiO2 spheres were resulted with good sphericity when the ammonia is in the range of 6.0-7.5 ml.

Polymersomes with Rapid K+-Triggered Drug-Release Behaviors.

A novel type of smart polymersomes with rapid K+-triggered drug-release properties is developed in this work. Block copolymers with biocompatible poly(ethylene glycol) (PEG) as the hydrophilic block and poly(N-isopropylacrylamide-co-benzo-18-crown-6-acrylamide) (PNB) copolymer as the K+-responsive block are successfully synthesized. Because of the presence of 18-crown-6 units, the PEG-b-PNB block copolymers exhibit excellent K+-dependent phase-transition behaviors, which show a hydrophilic-hydrophobic state in simulated extracellular fluid and present a hydrophilic-hydrophilic state in simulated intracellular fluid. Polymersomes with regular spherical shape and good monodispersity are prepared by the self-assembly of the PEG-b-PNB block copolymers. Both hydrophilic fluorescein isothiocyanate-dextran and hydrophobic doxorubicin are selected as model drugs and are successfully encapsulated into the PEG-b-PNB polymersomes. After being placed in a simulated intracellular fluid with high K+ concentration, the PEG-b-PNB polymersomes immediately disassemble accompanied by the rapid and complete release of drugs. Such K+-responsive polymersomes with the desired drug-release properties provide a novel strategy for advanced intracellular drug delivery and release, which can enhance the safety and efficacy of cancer therapy.

Investigation on the catalytic activity of aminosilane stabilized gold nanocatalysts towards the reduction of nitroaromatics

In situ preparation of gold nanoparticles (AuNPs) in the presence of silicate matrix, N1-(3-trimethoxysilylpropyl)diethylenetriamine (TPDT) and cetyltrimethylammonium bromide (CTAB), using strong reducing agents sodium borohydride (NaBH4) and hydrazine (N2H4) was established and their catalytic abilities were examined by choosing industrially important model reactions, in order to find the best reducing agent for the preparation of catalytically more active AuNPs. The prepared AuNPs were characterized using UV–vis absorption spectroscopy, XRD, HRTEM, EDX and SAED analyses. The AuNPs produced by NaBH4 showed relatively good mono-dispersion and small size than the AuNPs formed by N2H4. The catalytic activity of AuNPs produced by NaBH4 was found to be better than the AuNPs produced by N2H4 towards the reduction of various nitroaromatics. The turn over frequency (TOF) values obtained for the catalytic reduction of nitrobenzene (NB), 4-nitrophenol (4-NP) and 4-nitroaniline (4-NA) using the TPDT-Au-CTAB-NaBH4 catalyst are 0.312, 0.714 and 1.00s−1, respectively. Moreover, the rate constant (k) value obtained for the reduction of 4-NP is very high when compared to the reported results.

Controllable Growth of Monodisperse Multilayered Three-Dimensional Simonkolleite and Its Supercapacitor Activity

A unique multilayered three-dimensional (3D) simonkolleite with good monodispersity was successfully synthesized by a simple hydrothermal method. Against the preference for being two-dimensional (2D) nanoplate morphologies, the 3D structure growth was attributed to a novel molecule structure upon ionization of a soluble long-chain quaternary ammonium carboxylic acid. Ion-adjusted experiments were designed and carried out to make deep insight into the morphology revolution versus ionic environment, indicating that the ionized acid not only provided an essential prerequisite for forming simonkolleite but also acted as a morphological directing agent to assist the formation of the final 3D morphology. We further demonstrated the utility of the multilayered 3D simonkolleite as an electrode material for a supercapacitor which provided improved electrochemical performance compared with 2D simonkolleite.

RNA aptamer-based electrochemical aptasensor for C-reactive protein detection using functionalized silica microspheres as immunoprobes

C-reactive protein (CRP) is a widely accepted biomarker of cardiovascular disease and inflammation. In this study, a RNA aptamer-based electrochemical sandwich type aptasensor for CRP detection was described using the functionalized silica microspheres as immunoprobes. Silica microspheres (Si MSs), which have good monodispersity and uniform shape, were firstly synthesized. The silica microspheres functionlized with gold nanoparticles (Au NPs) provided large surface area for immobilizing signal molecules (Zinc ions, Zn2+) and antibodies (Ab). RNA aptamers, which were specific recognized to CRP, were assembled on the surface of Au NPs modified electrode via gold-sulfur affinity. In the presence of CRP, a sandwich structure of aptamer-CRP-immunoprobe was formed. Square wave voltammetry (SWV) was employed to record the sensing signal, and a clearly reductive peak corresponding to Zn2+ at about −1.16V (vs. SCE) was obtained. Under optimal conditions, the aptasensor showed wide linear range (0.005ngmL−1 to 125ngmL−1) and low detection limit (0.0017ngmL−1 at a signal-to-noise ratio of 3). Some possible interfering substance was also investigated, and the results obtained showed that the aptasensor possessed good selectivity. When the aptasensor was applied to real serum samples analysis, the satisfied results were obtained, indicating that the aptasensor possessed potential real application ability.

Synthesis of transparent oil dispersion of monodispersed calcium carbonate nanoparticles with high concentration

The preparation of monodispersed inorganic nanoparticles is of great interest for many applications. In this article, transparent oil dispersion of monodispersed amorphous CaCO3 nanoparticles with high concentration and long‐term stability were controllably prepared by a reverse microemulsion method. The effects of the addition amount of extra minute water and (NH4)2CO3 as novel assistant promoter, reaction temperature, Ca(OH)2/CaO mole ratio were explored. The optimum synthesis conditions were achieved. The as‐prepared transparent oil nanodispersion had a good monodispersity, a uniform particle size of 8–10 nm, a high stability of over 12 months, a high solid content of 38 wt% (Ca content of about 15.5 wt%) and a high total base number of 416 mgKOH/g. The preparation process was further investigated by polarized optical microscope and Fourier transform infrared. This nanodispersion will find a promising applicability as an excellent nanodetergent in the fields of automobile and marine lubricants. © 2017 American Institute of Chemical Engineers AIChE J, 63: 3663–3669, 2017

Ultrafast Synthesis of Novel Hexagonal Phase NaBiF4 Upconversion Nanoparticles at Room Temperature.

Upconversion (UC) nanoparticles (UCNPs) have evoked considerable attention in many fields owing to their fascinating features. However, rigorous synthesis conditions and expensive raw materials often limit their further applications. Here, a novel hexagonal phase NaBiF4 UC matrix through a very facile method (one min only at room temperature) is synthesized. The nanoparticles show good monodispersity with uniform size. Under the 980 nm irradiation, Yb3+ /Ln3+ (Ln = Er, Ho, Tm) codoped NaBiF4 nanoparticles show excellent UC luminescence (UCL). This super facile synthesis strategy and excellent matrix materials enable to achieve UCL in such low temperature, opening a new gateway for the UCNPs applied to a variety of areas in the future.

Mono-dispersed LiFePO4@C core-shell [001] nanorods for a high power Li-ion battery cathode

Abstract Monodispersed LiFePO4 [001] nanorods have been successfully synthesized via a conventional hydrothermal route with Li2SO4, FeSO4 and KH2PO4 as precursors. Subsequently, in virtue of the good monodispersibility LiFePO4@C core-shell [001] nanorods are facilely prepared by employing a carbon coating process on the obtained monodispersed LiFePO4 [001] nanorods. On the basis of the experimental results, a possible formation mechanism of the monodispersed LiFePO4 [001] nanorods has been proposed. Due to the full carbon coating, size reducing in [010] and the perfect olivine crystal lattice, the LiFePO4@C core-shell [001] nanorods exhibit excellent rate capacity and stable cycle performance.