Modification Of Nanoparticles Research Articles

Magnetic WS2 nanosheets functionalized by biomimetic lipids with enhanced dispersibility for combined photothermal and chemotherapy therapy

In recent years, multi-target combination therapy has received extensive attention as a method to improve the effectiveness of tumor treatment. In this study, the tungsten disulfide nanosheets (WS2) were firstly modified with iron oxide nanoparticles (IONPs), and then the surface was modified with lipids, to construct a lipid-modified magnetic WS2 composite nanomaterial system (mWS2-lipid). The nanocomposites exhibited high doxorubicin (DOX)-loading amount (179.53 ± 3.24%) and excellent photothermal property, which can reach 60.7 °C in 10 min under near-infrared (NIR) light irradiation of 808 nm, 2 W/cm2. After lipid modification, the dispersity and stability of nanoparticles in water, phosphate buffered saline (PBS) and cell culture medium were greatly improved. The attached DOX exhibits an obvious dual response of pH and NIR. Cell experiment results show that mWS2-lipid has no obvious cytotoxicity, as for the cytotoxicity of DOX-loaded material as well as photothermal ablation, it was concentration-dependent. Finally, in vivo photothermal experiments confirmed that the modification of the material by lipids increased its accumulation level in tumors. MWS2-lipid is therefore a good choice for cancer therapy combining photothermal treatment with chemotherapy.

Improving electrochemical performance of LiNi0.9Co0.05Mn0.05O2 cathode material by coating with nano-LiNbO3 layer

The nano-LiNbO3 layer coated LiNi0.9Co0.05Mn0.05O2 (LNbO-LNCMO) cathode material was synthesized by using a facile solid-state reaction method. The starting materials, Ni0.9Co0.05Mn0.05(OH)2 precursor, lithium hydroxide (LiOH．H2O), and ∼500 nm niobium pentoxide (Nb2O5) powders, were mixed and then one-step sintered at high temperature to obtain the resultant powder. Examinations via SEM/EDS, XPS and FE-TEM revealed a ∼10 nm LiNbO3 layer on the surface of the resultant LNbO-LNCMO. The LNbO-LNCMO showed discharge capacities of 218.6 and 171.8 mAh/g at discharging rates of 0.1 and 5.0 C, respectively. These results improved the corresponding values for a pristine LNCMO sample at 212.3 and 105.1 mAh/g. After 50 charge/discharge cycles, the LNbO-LNCMO retains 93.3 % of its initial capacity, compared with an 80.6 % retention rate for pristine LNCMO. EIS and PITT analyses show that the electronic resistance of LNbO-LNCMO is much lower than that of pristine LNCMO and the higher apparent Li+ ion diffusion coefficients are obtained. The LNbO-LNCMO also show an improved thermal stability over the pristine LNCMO according to DSC analysis. These results confirm that a nano-LiNbO3 layer on the surface of LNCMO significantly reduces the reactions between electrode materials and electrolytes, which improves electrochemical performance. In this regard, the simple synthesis process with nanoparticle modification offers a promising new approach for the battery industry to fabricate novel cathode materials with high performance.

IN SITU ENCAPSULATION OF NICKEL NANOPARTICLES IN POLYSACCHARIDE SHELLS DURING THEIR FABRICATION BY ELECTRICAL EXPLOSION OF WIRE

Nickel nanoparticles are obtained by electrical explosion of wire under the action of a high-voltage discharge followed by condensation in an inert gas medium. When butane is added to the gas medium, a carbon shell is deposited onto the condensing nickel particles. Immediately after the synthesis, liquid-phase modification of nanoparticles is carried out with aqueous solutions of polysaccharides agarose and gellan. As a result, a polymer shell is formed on particles of Ni and nickel particles coated with a carbon shell (Ni@C). The dispersity, crystalline structure, and magnetic properties of Ni and Ni@C nanoparticles are characterized by transmission microscopy, X-ray diffraction analysis, and vibration magnetometry. The total carboncontent on the surface of the nanoparticles is determined by thermal analysis with simultaneous mass spectrometry. It is shown that, under the studied conditions, polysaccharides are deposited onto the nanoparticles in amounts up to 2 wt % to form a shell with a thickness of about 4 nm. When agarose is used as a modifier, the content of the polysaccharide increases with the concentration of the modifying solution. When gellan is used as a modifier, a more complex concentration dependence is observed: an initial increase is followed by a decrease in the amount of deposited polysaccharide. The results are discussed from the viewpoint of the influence of the molecular weight of a polymer on the adsorption process.

Enhanced and stable gas sensing performance towards NH3 with AuCu alloy nanoparticles modification over SnO2

Enhanced and stable gas sensing performance towards NH3 with AuCu alloy nanoparticles modification over SnO2

Highly adsorptive removal of oxytetracycline in water environment using polyanion modified alumina nanoparticles

In this study, adsorptive removal of an antibiotic oxytetracycline (OTC) using polyanion poly(2-acrylamide-2-methylpropane sulfonic acid), PAMPs modified α-Al2O3 nanoparticles (PAMNA) was investigated. Surface modification of α-Al2O3 nanoparticles by PAMPs enhanced the removal efficiency of OTC significantly from 35.5 to 90.7 %. The optimum conditions for adsorptive removal of OTC using PAMNA were found to be pH 4, contact time 120 min and adsorbent dosage 20 mg/mL. Under selected conditions, the removal efficiency of OTC using PAMNA was greater than 90 % while the maximum adsorption capacity reached 140.2 mg/g. After three regenerations, the removal efficiencies of OTC were still higher than 75 %. The results of adsorption isotherms of OTC on PAMNA and the surface charge change of PAMNA indicate that both electrostatic and non-electrostatic interactions control OTC adsorption on PAMNA.

High performance CO2 Absorption/Desorption using Amine-Functionalized magnetic nanoparticles

In the current study, for the first time, a variety of amino acid groups, including arginine, histidine, and glycine, were added to Fe3O4 nanoparticles to achieve desired mass and heat transfer properties in CO2 absorption/desorption experiments. For this purpose, different concentrations of synthesized nanoparticles were employed in base fluid (10 wt% methyldiethanolamine) in a semi batch experiment at ambient pressure for CO2 absorption and desorption. The experimental results clearly indicated that modification of iron oxide nanoparticles could enhance CO2 absorption and stripping significantly, as a result of higher stability of nanoparticles and presence of amino groups at the nanoparticles' structure. Compared to bare Fe3O4, Fe3O4@arginine, Fe3O4@histidine, and Fe3O4@glycine demonstrated 23%, 17%, and 10% increase in CO2 absorption capacity, respectively. By using chemical agent as stabilizer species and by modified thermal properties of solution, magnetic nanoparticles promoted CO2 desorption to a great extent. Therefore, Fe3O4@arginine, Fe3O4@histidine, and Fe3O4@glycine nanofluids improved CO2 desorption enhancement by 48.2%, 47.2%, and 46.1% at 70 °C, respectively.

Bilayer-Coating Strategy for Hydrophobic Nanoparticles Providing Colloidal Stability, Functionality, and Surface Protection in Biological Media.

The surface chemistry of nanoparticles is a key step on the pathway from particle design towards applications in biologically relevant environments. Here, a bilayer-based strategy for the surface modification of hydrophobic nanoparticles is introduced that leads to excellent colloidal stability in aqueous environments and good protection against disintegration, while permitting surface functionalization via simple carbodiimide chemistry. We have demonstrated the excellent potential of this strategy using upconversion nanoparticles (UCNPs), initially coated with oleate and therefore dispersible only in organic solvents. The hydrophobic oleate capping is maintained and a bilayer is formed upon addition of excess oleate. The bilayer approach renders protection towards luminescence loss by water quenching, while the incorporation of additional molecules containing amino functions yields colloidal stability and facilitates the introduction of functionality. The biological relevance of the approach was confirmed with the use of two model dyes, a photosensitizer and a nitric oxide (NO) probe that, when attached to the surface of the UCNPs, retained their functionality to produce singlet oxygen and detect intracellular NO, respectively. We present a simple and fast strategy to protect and functionalize inorganic nanoparticles in biological media, which is important for controlled surface engineering of nanosized materials for theranostic applications.

Strategie zur Beschichtung von hydrophoben Nanopartikeln mit einer Doppelschicht für kolloidale Stabilität, Funktionalität und Oberflächenschutz in biologischen Medien

AbstractDie Oberflächenchemie von Nanopartikeln ist ein wichtiger Schritt auf dem Weg vom Partikeldesign zur Anwendung in biologisch relevanten Umgebungen. Hier wird eine auf einer Doppelschicht (Bilayer) basierende Strategie für die Oberflächenmodifikation von hydrophoben Nanopartikeln vorgestellt, die diesen eine ausgezeichnete kolloidale Stabilität in wässriger Umgebung und einen guten Schutz gegen Auflösung verleiht und gleichzeitig eine Oberflächenfunktionalisierung durch einfache Carbodiimid‐Kopplungschemie ermöglicht. Wir haben das herausragende Potenzial dieser Strategie anhand von Upconversion‐Nanopartikeln (UCNPs) demonstriert, die ursprünglich mit Oleat beschichtet und daher nur in organischen Lösungsmitteln dispergierbar waren. Die hydrophobe Oleatbeschichtung bleibt dabei erhalten und bildet nach Zugabe von weiterem Oleat eine Doppelschicht. Dieser Ansatz schützt vor Lumineszenzlöschung durch Wassermoleküle, während der Einbau zusätzlicher Moleküle mit Aminogruppen in die Doppelschicht deren kolloidale Stabilität erhöht und die Funktionalisierbarkeit erleichtert. Die biologische Relevanz des Ansatzes wurde durch die Verwendung von zwei Modellfarbstoffen gezeigt, einem Photosensibilisator und einer Stickoxid‐ (NO−) Sonde, die, wenn sie an die Oberfläche der UCNPs gebunden sind, ihre Funktionalität zur Erzeugung von Singulett‐Sauerstoff bzw. zum Nachweis von intrazellulärem NO beibehalten. Wir stellen eine einfache und schnelle Methode zum Schutz und zur Funktionalisierung von anorganischen Nanopartikeln in biologischen Medien vor, die für die kontrollierte Oberflächengestaltung von Nanomaterialien für theranostische Anwendungen wichtig ist.

Parameterisation and cellular evaluation of poly(ethylene) oxide-coated erbium oxide in MCF-7 cells as MRI diagnostic nanofibres

The novelty of this work is the conjugation of poly(ethylene) oxide (PEO) with the erbium oxide (Er2O3) nanoparticles using the electrospinning technique. In this work, synthesised PEO-coated Er2O3 nanofibres were characterised and evaluated for their cytotoxicity to assess their potential use as diagnostic nanofibres for magnetic resonance imaging (MRI). PEO has significantly impacted nanoparticle conductivity due to its lower ionic conductivity at room temperature. The findings showed that the surface roughness was improved over the nanofiller loading, implying an improvement in cell attachment. The release profile performed for drug-controlling purposes has demonstrated a stable release after 30 min. Cellular response in MCF-7 cells showed high biocompatibility of the synthesised nanofibres. The cytotoxicity assay results showed that the diagnostic nanofibres had excellent biocompatibility, indicating the feasibility for diagnosis purposes. With excellent contrast performance, the PEO-coated Er2O3 nanofibres developed novel T2 and T1-T2 dual-mode MRI diagnostic nanofibres leading to better cancer diagnosis. In conclusion, this work has demonstrated that the conjugation of PEO-coated Er2O3 nanofibres improved the surface modification of the Er2O3 nanoparticles as a potential diagnostic agent. Using PEO in this study as a carrier or polymer matrix significantly influenced the biocompatibility and internalisation efficiency of the Er2O3 nanoparticles without triggering any morphological changes after treatment. This work has suggested permissible concentrations of PEO-coated Er2O3 nanofibres for diagnostic uses.

Development of Stereocomplex Polylactide Nanocomposites as an Advanced Class of Biomaterials-A Review.

This review paper analyzes the development of advanced class polylactide (PLA) materials through a combination of stereocomplexation and nanocomposites approaches. The similarities in these approaches provide the opportunity to generate an advanced stereocomplex PLA nanocomposite (stereo-nano PLA) material with various beneficial properties. As a potential "green" polymer with tunable characteristics (e.g., modifiable molecular structure and organic-inorganic miscibility), stereo-nano PLA could be used for various advanced applications. The molecular structure modification of PLA homopolymers and nanoparticles in stereo-nano PLA materials enables us to encounter stereocomplexation and nanocomposites constraints. The hydrogen bonding of D- and L-lactide fragments aids in the formation of stereococomplex crystallites, while the hetero-nucleation capabilities of nanofillers result in a synergism that improves the physical, thermal, and mechanical properties of materials, including stereocomplex memory (melt stability) and nanoparticle dispersion. The special properties of selected nanoparticles also allow the production of stereo-nano PLA materials with distinctive characteristics, such as electrical conductivity, anti-inflammatory, and anti-bacterial properties. The D- and L-lactide chains in PLA copolymers provide self-assembly capabilities to form stable nanocarrier micelles for encapsulating nanoparticles. This development of advanced stereo-nano PLA with biodegradability, biocompatibility, and tunability properties shows potential for use in wider and advanced applications as a high-performance material, in engineering field, electronic, medical device, biomedical, diagnosis, and therapeutic applications.

Co-application of copper oxide nanoparticles and Trichoderma harzianum with physiological, enzymatic and ultrastructural responses for the mitigation of salt stress

Chemical contamination or nutrient pollution is concerning for health, environmental, and economic reasons. Ecofriendly surface modification of nanoparticles is a consistent challenge for agricultural purposes. In response to this environmental concern, CuO-NPs synthesized through biological method using green source and characterized for morphological and structural features through SEM (scanning electron microscope) and TEM (transmission electron microscope) spectroscopy. Our research findings illustrate that the presence of salt stress induces a notable decline in both physiological and biochemical parameters within plants. Nevertheless, the utilization of T. harzianum and CuO-NPs exhibited a mitigating effect on the detrimental consequences induced by salt stress in plants. The application of T. harzianum and the simultaneous co-inoculation with CuO-NPs notably enhanced fresh biomass and facilitated vegetative growth in comparison to the control group. Furthermore, the exposure of both T. harzianum inoculum and Copper oxide nanoparticles resulted in a significant reduction of oxidative stresses, including reactive oxygen species (ROS) levels, H2O2, and lipid peroxidation (MDA) levels in the above-ground parts of the plant, while also minimizing electrolyte leakage (EL) by reducing root growth. Additionally, the co-inoculation of the endophyte and CuO-NPs led to a significant enhancement in antioxidant enzymatic activities, such as superoxide dismutase (SOD) and chitinase (CAT) activity in the above-ground parts, under salt stress conditions. The inoculum, along with its combination with CuO-NPs, decreased electrolyte conductivity and improved total chlorophyll contents as compared to the control. The combined application of T. harzianum and CuO-NPs improved salt tolerance in A. thaliana plants by triggering salt-associated gene expression. These findings suggest that the application of T. harzianum and CuO-NPs can considerably promote leaf anatomical changes in A. thaliana and have ability to enhance salt tolerance, particularly in saline areas.

Modification of iron sulfide nanoparticles by hyaluronate: Enhanced stability, transport, and reactivity

Nanoparticulate iron sulfides (nano-FeS) with high reactivity have shown tremendous potential as an effective environmentally friendly material for in situ soil and groundwater remediation. However, bare nano-FeS are susceptible to aggregation and oxidation aging, which limits their reactivity and engineering application because of limited mass transfer and formation of the passivation layer. Herein, nano-FeS were modified by surface functionalization using sodium hyaluronate (SoH), and the effect of modification on colloidal stability, sedimentation, oxidation resistance, mobility, and reactivity with Cr(VI) was investigated. The results demonstrated that SoH could stabilize FeS (SoH-FeS) using SoH-to-FeS molar ratios of ≥0.001, with the stabilizer effectively soldered onto the surfaces as bidentate bridging through the carboxylic group, providing electrostatic and steric repulsion that prevented particle aggregation. Compared with bare FeS, the sedimentation rates of modified FeS decreased and oxidation resistance and transport increased significantly. The improved transport performance of SoH-FeS was further achieved by decreasing the injection mass concentration and increasing the flow rate. SoH-FeS increased the Cr(VI) sequestration efficiency from 57.5% to 99.9% relative to pristine FeS, and the removal processes followed the pseudo-second-order kinetic model (R2 ≥ 0.998). The coexistence of reaction products (i.e., α-FeOOH, polysulfide, and Cr(OH)3) revealed by X-ray diffraction and X-ray photoelectron spectroscopy analysis with different Cr speciation concentrations in the aqueous phase suggested surface sorption (26.8%) and reduction/precipitation (73.2%) were the dominant removal mechanisms. Higher pH and humic acid concentrations modestly inhibited Cr(VI) removal efficiency. The results demonstrate an efficient method for enhancing nano-FeS mobility and reactivity for in situ remediation of contaminated soils and groundwater.

Preparation and Application of a Bioorganic Nanoparticle-Enhanced PDL1-Targeted Small-Molecule Probe.

Programmed death ligand 1 (PDL1) is a specific molecular target for the diagnosis and immunotherapy of solid tumors. PET imaging can be used for noninvasive assessments of PDL1 expression in tumors to aid in therapy selection. The most frequently reported small-molecule radiotracer of PDL1 is limited by low imaging specificity, short residence time, and singular functionality. Here, we combined a biocompatible melanin nanoprobe with the PDL1-binding peptide WL12 to construct a novel radiotracer, 124I-WPMN, to enhance PDL1 targeting. The radiochemical purity of 124I-WPMN was >95%, and uptake in A549PDL1 cells was 1.49 ± 0.08% at 2 h. The uptake was blocked by WL12 (0.39 ± 0.03%, P < 0.0001). This novel radiotracer showed a higher affinity for PDL1 (Kd = 18.5 nM) than 68Ga-NOTA-WL12 (Kd = 24.0 nM). Micro-PET/CT imaging demonstrated specific uptake and a high signal-to-noise ratio in an A549PDL1 xenograft mouse model with a tumor-to-muscle ratio of 27.31 ± 7.03 at 2 h. The levels increased or remained steady for more than 72 h, and tumor uptake was significantly higher than 68Ga-NOTA-WL12, at 6.08 ± 0.62 at 2 h. Prolonged retention of 124I-WPMN makes it possible to conduct PET/MRI imaging over long periods and to perform various imaging techniques. A clear advantage of 124I-WPMN over 68Ga-NOTA-WL12 was observed for PDL1-targeted PET imaging after nanoparticle modification, supporting the utility of 124I-WPMN PET imaging as an effective diagnostic tool for optimizing PDL1-targeted therapies.

Hot-work die steel with superior mechanical properties at room and high temperatures prepared via a combined approach of composition design and nanoparticle modification

Hot-work die steel with excellent strength and toughness can improve the precision of the die and prolong its service life. However, this is very difficult to achieve because of the opposing relationship between strength and plasticity. In this paper, we propose a combined approach of composition design and nanoparticle modification to overcome this difficulty. A novel hot-work die steel with reinforced trace nano-(TiC–TiB2) was fabricated using a traditional method. It had an improved microstructure, which consists of fine martensitic laths with high dislocation density, abundant small precipitates, and small and dispersed residual austenite. This expected microstructure improved the work hardening and uniform deformation ability of the steel, resulting in superior comprehensive mechanical properties. The yield strength and impact toughness of the novel hot-work die steel at room temperature were 1464 MPa and 597 J/cm2, respectively, increases of 121 MPa and 265 J/cm2, respectively, compared to the values for advanced and widely used traditional H13 steel. In particular, the impact toughness of the novel hot-work die steel at room temperature was approximately 42.5% and 33.0% higher than the impact toughness of H13 containing 0.01 and 0.02 wt% nanoparticles, respectively. Furthermore, the yield strength, ultimate tensile strength, and elongation of novel hot-work die steel at 500 °C were 1078 MPa,1103 MPa, and 40.4%, respectively, increases of 85 MPa, 86 MPa, and 4.2%, respectively, compared to values of the blank that was used in this work. This work shows new prospects for the development of hot-work die steel with excellent strength and toughness.

83‐1: Improved performance of EL‐QD display through surface modified QDs and inorganic nanoink

We demonstrated the ligand exchange procedure on the InP base green QDs and Zn(Mg)O surface to improve of efficiency at EL‐QDs device. Performace of EL‐QDs device was imporved by control of electron mobility and chargen balance through ligand exchange in QDs surface. Moverover, we can prevented QD aggregation of EML throgh surface modification of electron transfer nanoparticles on inverted top emitting device.

Gold Nanoparticles with Natural Ingredients as Anti-Aging: A Systematic Review

Aging is a natural process characterized by physiological skin changes. It starts to appear when individuals are in their thirties, making it necessary to use anti-aging products with natural ingredients which are safe even though the penetration is relatively low into the skin. Natural ingredients that can be used are antioxidants that can inhibit aging and can act as bioreductants on gold nanoparticles. Gold nanoparticles can increase penetration into the target cells because of their small size with large surface area. This review article aimed to collect data relating to the development of gold nanoparticles with natural ingredients as anti-aging agents. This review searched through the PubMed and ScienceDirect databases with such keywords as aging, anti-aging, plant extract, antioxidants, and gold nanoparticles. The inclusion criteria were articles in English, available in a full-text version, and published in the last 10 years. Research on the use of natural ingredients as anti-aging agents found that natural ingredients perform better than chemical comparators. Gold nanoparticles are also reported to have been widely used in anti-aging products. Their activity is even better given the low IC50 value and a higher percentage of inhibition compared to those of the extracts without nanoparticle modification. It is reported that gold nanoparticles with natural ingredients as anti-aging agents have a better effect as opposed to purely natural ingredients.

How to Develop Drug Delivery System Based on Carbohydrate Nanoparticles Targeted to Brain Tumors.

Brain tumors are the most difficult to treat, not only because of the variety of their forms and the small number of effective chemotherapeutic agents capable of suppressing tumor cells, but also limited by poor drug transport across the blood-brain barrier (BBB). Nanoparticles are promising drug delivery solutions promoted by the expansion of nanotechnology, emerging in the creation and practical use of materials in the range from 1 to 500 nm. Carbohydrate-based nanoparticles is a unique platform for active molecular transport and targeted drug delivery, providing biocompatibility, biodegradability, and a reduction in toxic side effects. However, the design and fabrication of biopolymer colloidal nanomaterials have been and remain highly challenging to date. Our review is devoted to the description of carbohydrate nanoparticle synthesis and modification, with a brief overview of the biological and promising clinical outcomes. We also expect this manuscript to highlight the great potential of carbohydrate nanocarriers for drug delivery and targeted treatment of gliomas of various grades and glioblastomas, as the most aggressive of brain tumors.

Effects of stably dispersed carbon nanotube additives in yellow oleander methyl ester-diesel blend on the performance, combustion, and emission characteristics of a CI engine

In the present investigation, we studied the influence of carbon nanotubes (CNTs) on the overall performance of a diesel engine using 20% (by volume) of yellow oleander methyl ester and 80% diesel (Y20) with and without CNT nano additives. The surface modification of CNT nanoparticles was observed, using ultraviolet–visible spectrometry, in the Y20 with different concentrations of QPAN 80 surfactant. The optimal concentration is determined to be 1:4. Nano additives were blended in Y20 blends at concentrations of 25, 50, and 75 ppm employing an ultrasonicator with optimal ratio. These samples were examined for physicochemical properties and tested in a compression ignition (CI) engine. Significant enhancements in performance and emission parameters were observed for the Y20C50 blend: Brake thermal efficiency improved by 15.5%, and we observed a reduction in brake-specific fuel consumption by 20.57%, carbon monoxide by 26.8%, unburnt hydrocarbon by 35.7%, and nitrogen oxides by 13.2%. Similarly, the addition of CNTs in the Y20 blend improved cylinder pressure, heat release rate, and rate of pressure rise and reduced ignition delay and combustion duration. In summary, CNTs were discovered to be suitable fuel additives for the Y20 blend to improve overall engine performance and reduce emissions.

Amplification of SERS Signal of Methotrexate Using Beta-Cyclodextrin Modified Silver Nanoparticles

The paper describes the use of native β-cyclodextrin (CD) for the modification of silver nanoparticles (AgNPs) in order to improve the determination of the anticancer drug methotrexate (MTX) using surface-enhanced Raman spectroscopy (SERS). A control experiment with unmodified AgNPs showed that the strong SERS signal of MTX can only be achieved in alkaline media. However, competitive interactions and the strong background signal of human body fluid components significantly challenge MTX determination in real samples. While previous reports propose the use of thorough sample pretreatment (e.g., solid phase extraction), the application of CD-modified AgNPs increases the SERS signal of MTX in neutral media by seven times which enables simplifying the analysis and improving its accuracy by reducing the influence of endogenous components of body fluids. A detailed study of the synthesis conditions (CD concentration and reaction time) and SERS registration conditions (pH, NaCl concentration, dilution of urine samples) was performed to maximize the analytical signal and signal-to-noise ratio. The final assay was tested for MTX determination in artificially spiked samples of real human urine. The results demonstrated that MTX can be determined within the concentration range suitable for therapeutic drug monitoring (20–300 μg mL−1) with satisfactory precision (6–15% RSD), accuracy (95–111% apparent recovery), and limit of detection (0.3 μg mL−1).

Hierarchically Structured Nanotube Arrays as Heterogenous Photocatalysts for Highly Efficient Broadband Photoinduced Controlled Radical Polymerization

Highly ordered TiO2 nanotube arrays (TNTAs) and their heterostructure nanocomposites by structural engineering design were utilized as heterogeneous photocatalysts for highly efficient broadband photoinduced controlled radical polymerization (photoCRP), including photoATRP and PET-RAFT. Highly efficient broadband UV-visible light responsive photoCRP was achieved by combining the acceleration effects of electron transfer derived from the distinctive highly ordered nanotube structure of TNTAs and the localized surface plasmon resonance (LSPR) effect combined with the formation of the Schottky barrier via modification of Au nanoparticles. This polymerization system was capable to polymerize acrylate and methacrylate monomers with high conversion, "living" chain-ends, tightly regulated molecular weights, and outstanding temporal control properties. The heterogeneous nature of the photocatalysts enabled simple separation and effective reusability in subsequent polymerizations. These results highlight the modular design of highly efficient catalysts to optimize the controlled radical polymerization process.