Flower-like Nanomaterials Research Articles

Intracellular NO Delivery by Si-Based Ni Composite Nanoflowers

Flower-like nanomaterials have received great attention due to their large surface area, enhanced charge transfer, and 3D structure, all of which contribute to their applications in drug delivery, cell imaging, biosensors, and other biomedical applications. Two core–shell-structured Si-based Ni composite nanoflowers (Si@NiOOH and Si@Ni) were prepared as NO donors using a modified chemical bath deposition method and thermal reduction. The Si-based Ni composite nanoflowers showed low cytotoxicity toward mouse embryonic fibroblasts when applied at concentrations of up to 2 mg·mL–1. NO-loaded Si@NiOOH and Si@Ni (NO⊂Si@NiOOH and NO⊂Si@Ni, respectively) were obtained by charging Si@NiOOH and Si@Ni with NO at 10 atm for 72 h. The NO storage/release profiles of these materials were then compared via electrochemiluminescence analysis. NO⊂Si@Ni released 0.07 μmol·mg–1 NO over 1.1 h in phosphate-buffered saline at 37 °C, thereby demonstrating that it can fully satisfy the requirements for clinical usage. Furthermore, these nanoflowers presented a composition-dependent NO-delivery ability and excellent antibacterial activities toward Escherichia coli and Staphylococcus aureus. Our study on the NO-delivery capability of bioactive Ni composite nanoflowers can improve the potency of NO donors available for therapeutic applications.

High Sensing Performance Toward Acetone Vapor Using TiO2 Flower-Like Nanomaterials

For real-application gas sensors, high performances (response, selectivity, response/recovery time and stability) are demanded. An effective strategy is applying nanomaterials in gas sensors. In this study, the anatase TiO2 flower-like nanomaterials (FLNMs) are prepared through a one-step hydrothermal method which exhibit high-performance toward acetone vapor. TiO2 FLNMs sensors property are characterized at optimal working temperature of 330 °C with selectivity (acetone), response (S = 33.72 toward 250 ppm acetone), linear dependence (R2 = 0.9913), response/recovery time (46/24 s toward 250 ppm acetone) and long-term stability (30 days). These demonstrate that TiO2 FLNMs get a high performance for acetone sensor. Moreover, the limit of detection of acetone is 0.65 ppm which is lower than that of exhaled air for diabetes (0.8 ppm), indicating that TiO2 FLNMs gas sensor gets potential application in medical diagnosis.

Ultrasensitive flower-like TiO2/Ag substrate for SERS detection of pigments and melamine.

TiO2 flower like nanomaterials (FLNMs) are fabricated via a hydrothermal method and Ag nanoparticles (NPs) are deposited via electron beam evaporation. Several biological pigments (CV, R6G and RhB) are selected as target molecules to investigate their surface enhanced Raman scattering (SERS) property. The results demonstrate ultrasensitivity and high reproducibility. They reveal that the limit of detection (LOD) is 4.17 × 10−16 M and the enhancement factor (EF) is 2.87 × 1010 for CV, and the LOD is 5.01 × 10−16 M and 7.94 × 10−14 M for R6G and RhB, respectively. To assess the reproducibility on TiO2/Ag FLNMs SERS substrates, they are tested with 1.0 × 10−13 M of CV, 1.0 × 10−13 M of R6G and 1.0 × 10−11 M of RhB, respectively. The relative standard deviations (RSD) are less than 12.93%, 13.52% and 11.74% for CV, R6G and RhB, respectively. In addition, we carry out melamine detection and the LOD is up to 7.41 × 10−10 M, which is over 1000 times lower than the severest standards in the world. Therefore, the obtained TiO2 FLNMs have potential application in detecting illegal food additives.

Synthesis of the hybrid CdS/Au flower-like nanomaterials and their SERS application

The CdS flower-like nanomaterials (FLNMs) were synthesized by a facile hydrothermal method. With the help of the hydrophilic group on polyvinyl pyrrolidone molecules, the CdS FLNMs were decorated with Au nanoparticles (NPs) through in situ chemical reduction of HAuCl4. The hybrid CdS/Au FLNMs were investigated through surface-enhanced Raman scattering (SERS). It is found that they can detect crystal violet, Rhodamine B and malachite green as low as 1.0 × 10−8 M, 1.0 × 10−8 M, and 1.0 × 10-7 M respectively. In addition, the theoretical simulation was carried out by the discrete dipole approximation (DDA) method. It is found that the strong electric field of Au dimer and the coupling electric field between Au NPs and CdS FLNMs makes a significant improvement in SERS. Therefore, the hybrid CdS/Au FLNMs have a potential in applications such as detecting organics.

Porous 3D flower-like bismuth silicate@nitrogen-doped graphene nanomaterial as high-efficient catalyst for fuel cell cathode

Three-dimensional (3D) flower-like Bi2SiO5 nanomaterials (FLB) and 3D flower-like Bi2SiO5@nitrogen doped graphene nanomaterials (FLBNG) have been originally synthesized. Notably, as-synthesized FLB and FLBNG nanomaterials have not yet been discussed in previous reports. The FLBNG nanomaterials have been for the first time studied as the cathodic catalysts for Fuel cell. Research results have shown that the FLBNG-2 possesses perfectly 3D flower-like Bi2SiO5 with numerous uniformly coiled nanowires and exhibits good methanol immunity, high activity and high durability during oxygen reduction reaction (ORR) process under acidic and basic electrolytes. The value of onset potential (E0) for FLBNG-2 in alkaline electrolyte can reach to 1.091 V, Tafel slope of FLBNG-2 is 45.637 mV dec−1 and its limiting current density (JL) is 6.49 mA cm−2. Similarly, These ORR performances in acidic electrolyte are also better than those of 20 wt% commercial Pt/C and most of the associated reports. Thus, the FLBNG-2 could be a potential ORR catalyst, applied in the cathode of fuel cells to enhance the kinetic rate, decrease costs and enhance durability. And this synthesis method may be provide a good design to synthesize other 3D flower-like nanomaterials with desirable properties.

The fabrication of flower-like graphene/octadecylamine composites

Abstract Three-dimensional flower-like nanomaterials have wide application due to the large specific surface area. In this letter, the morphology of octadecylamine (ODA) from several common solvents is studied and it is found that from the chloroform and acetone solution, ODA assembles into petal-like structure, which further forms the spherical or flower-like architecture. Furthermore, the composite materials incorporated reduced graphene oxide (rGO) and ODA could well keep the flower-shaped structure of ODA. XRD results show that the introduction of graphene has little influence on the structure of ODA and contact angle test indicates good hydrophobic performance of the rGO/ODA material.

Application of three-dimensional flower-like nanomaterials in the fabrication of sandwich-type electrochemical immunosensors

A novel and ultrasensitive sandwich-type electrochemical immunosensor was developed for the quantitative detection of carcinoembryonic antigen (CEA) in this work.

Seed-Mediated Synthesis and Characterization of Ni Flower-Like Nanomaterials

Flower-like Ni nanoparticles in diameter of 200 approximately 250 nm were synthesized by a mild chemical solution method. They were composed of smaller single-crystal Ni grains with an average diameter of approximately 15 nm. XRD, EDS and HRTEM results show that these particles were mixed uniformly with iron oxide single crystals, which serve as seeds for the growth of the flower-like structure. And a possible growth mechanism was proposed. The transformer oil-based fluid with conductive Ni nanoflowers was prepared and the measurements indicate that the dielectric performance of transformer oil is improved using this sample as additive, which could attribute to their capability of electron scavenging.

Synthesis of F-Doped Flower-like TiO2 Nanostructures with High Photoelectrochemical Activity

We report on a novel and facile approach for the direct growth of F-doped flower-like TiO(2) nanostructures on the surface of Ti in HF solutions under low-temperature hydrothermal conditions. The influence of the experimental parameters such as temperature, reaction duration, and the HF concentration on the morphology and photoelectrocatalytic activity of the formed F-doped flower-like TiO(2) nanostructures was systematically studied. The presence of HF and the reaction time play an important role in the formation of the F-doped flower-like TiO(2) nanostructures. The synthesized novel F-doped TiO(2) flower-like nanomaterials possess good crystallinity and exhibit high photoelectrochemical activity for water-splitting and photodegradation of organic pollutants compared with P-25, which is currently considered to be one of the best commercial TiO(2) photocatalysts. The approach described in this study provides a simple and novel method to synthesize F-doped TiO(2) nanostructured materials that are ready for practical applications such as the photodegradation of wastewater.