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Li3VO4 (LVO) is a highly promising anode material for lithium-ion batteries, owing to its high capacity and stable discharge plateau. However, LVO faces a significant challenge due to its poor rate capability, which is mainly attributed to its low electronic conductivity. To enhance the kinetics of lithium ion insertion and extraction in LVO anode materials, a conductive polymer called poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) is applied to coat the surface of LVO. This uniform coating of PEDOT:PSS improves the electronic conductivity of LVO, thereby enhancing the corresponding electrochemical properties of the resulting PEDOT:PSS-decorated LVO (P-LVO) half-cell. The charge/discharge curves between 0.2 and 3.0 V (vs. Li+/Li) indicate that the P-LVO electrode displays a capacity of 191.9 mAh/g at 8 C, while the LVO only delivers a capacity of 111.3 mAh/g at the same current density. To evaluate the practical application of P-LVO, lithium-ion capacitors (LICs) are constructed with P-LVO composite as the negative electrode and active carbon (AC) as the positive electrode. The P-LVO//AC LIC demonstrates an energy density of 107.0 Wh/kg at a power density of 125 W/kg, along with superior cycling stability and 97.4% retention after 2000 cycles. These results highlight the great potential of P-LVO for energy storage applications.

In this study, the core-shell of Fe

The flexible surface-enhanced Raman scattering (SERS) sensor, which has the bionic 3D nanoarray structure of a beetle-wing substrate (BWS), was successfully prepared by replicated technology and thermal evaporation. The bionic structure was replicated with polydimethylsiloxane (PDMS) and then silver (Ag) nanoisland thin films were deposited by thermal evaporation. The deposition times and thicknesses (25–40 nm) of the Ag thin films were manipulated to find the optimal SERS detection capability. The Ag nanoisland arrays on the surface of the bionic replicated PDMS were observed by scanning electron microscope (SEM), X-ray diffraction (XRD), and contact angle, which can generate strong and reproducible three-dimensional hotspots (3D hotspots) to enhance Raman signals. The water pollutant, rhodamine 6G (R6G), was used as a model molecule for SERS detection. The results show that 35 nm Ag deposited on a PDMS-BWS SERS substrate displays the strongest SERS intensity, which is 10 times higher than that of the pristine BWS with 35 nm Ag coating, due to the excellent 3D bionic structure. Our results demonstrate that bionic 3D SERS sensors have the potential to be applied in wearable devices and sensors to detect biomolecules and environmental pollutants, such as industrial wastewater, in the future.

Nowadays, chronic kidney disease (CKD) becomes a principal barrier in clinical diagnosis and treatment. For clinical patients, chronic kidney disease will potentially lead to multiple lesion that increase the risk of mortality. The most significant challenge in CKD is detecting uremic toxins, including small water-soluble solutes (uric acid, urea and creatinine) and protein-bound solutes (p-cresol and indoxyl sulfate). Surface-enhanced Raman scattering (SERS) platform is rapid and sensitive nanotechnology for bio-detection. Thus, the floating-typed SERS substrate is prepared by embedded silver nanoparticles (AgNPs) on the poly (diallyldimethyl-ammonium) chloride (PDDA) modified graphene oxide (GO) nanosheets for the biomolecules and uremic toxins detection. The optimal interparticle distances of AgNPs are modulated to generate the strong “hot spots” for enhancing Raman signals. The characterizations of AgNPs/GO-PDDA nanosheets are evaluated by transmission electron microscopy, zeta potential, FTIR, X-ray photoelectron spectroscopy, and Raman spectroscopy. The results show that the floating SERS-active substrate provides quantitatively linear measurement (i.e., 3.8 × 10−2 ˜10-5 M of urea) and ultrasensitive SERS detection (i.e., detection limit of adenine: lower than 10-10 M) of biomolecules, which offers great potential for practical clinical applications in rapid and label-free detection of clinical uremic toxins.

Thermo-responsive Raman-enhanced nanocapsules were successfully fabricated by Pluronic® F127 (F127) decorated with gold nanoparticles (AuNPs) for surface-enhanced Raman scattering (SERS) detection of biomolecules. F127 nanocapsules changes from hydrophilicity (swelling) to hydrophobicity (de-swelling) when the temperature increases from 15 °C to 37 °C, owing to the lower critical solution temperature (LCST) of F127 is about 26.5 °C. The size of nanocapsules would be enormous shrinking from 160 nm to 20 nm, resulting in a significant decrease in the distance between AuNPs to enhance hot spot effect, which increases the sensitivity of SERS detection. Based on the thermo-sensitive behavior, the ratio of AuNPs and F127 would be manipulated to find the optimal SERS enhancement effect. SERS nanocapsules can rapidly detect biomolecules (adenine and R6G) with limit of detection (LOD) lower than 10

Attainment of excellent Raman enhanced effect in a surface-enhanced Raman scattering (SERS) substrate requires uniform and precise control over inter-particle distances of the metal nanoparticles on large surface area. Here, we report a facile fabrication of SERS substrate comprising uniformly distributed bilayer structure of silver (Ag) and gold (Au) nano-island arrays (NIA), deposited by thermal evaporation method and demonstrate its use for SERS detection of rhodamine 6G (R6G). In our SERS substrate, the mandatory Ag NIA layer acts as the main Raman signal enhancement layer while the layer of Au NIA helps to attenuate the background fluorescence and suppress the air exposure of highly reactive surfaces of Ag NIA, thus also acting as a protective layer and ensuring reproducibility of SERS sensing. The results show that bilayer structure of Ag-4 nm and Au-2 nm NIA SERS substrate exhibits the optimal signal-to-background (S/B) ratio (up to 7, compared with 1.35 of bare Ag-4 nm) and excellent reproducibility (~8% fluctuations in 7 sample tests, compared with ~34% fluctuations in bare Ag-4 nm). Due to the high sensitivity (the limit of detection

A crucial polymer intermediate, 4-[1-(4-hydroxyphenyl)cyclopentyl]-phenol (bisphenol CP), was developed from dicyclopentadiene (DCPD), a key byproduct of the C5 fraction in petrochemicals. On the basis of bisphenol CP, a diamine, 4,4&rsquo, ((cyclopentane-1,1-diylbis(4,1-phenylene))bis(oxy))-dianiline (cyclopentyl diamine, CPDA) was subsequently obtained through a nucleophilic substitution of bisphenol CP, followed by the hydrogenation process. By using the CPDA diamine, a series of polyimides with cyclopentyl (cardo) units on the backbone were prepared along with a reference polyimide (API-6F) based on 4,4&rsquo, (4,4&rsquo, (propane-2,2-diyl)bis(4,1-phenylene))bis(oxy)dianiline (BPAA), and 4,4&prime, (hexafluoroisopropylidene)-diphthalic anhydride (6FDA) for the exploration of structure-properties relationship. Thanks to the presence of cyclopentyl units, this type of cardo polyimides exhibited comparable tensile properties, especially a large elongation (25.4%). It is also worth noting that CPI-6F exhibited better solubility in organic solvents, such as NMP, DMAc, THF, and chloroform, than the other PIs. Gas separation properties were also evaluated for these cardo-type polyimides.

Novel transparent conductive films were successfully fabricated by forming graphene/PEDOT:PSS nanohybrids and then spin-coating the mixture onto glass substrates. The mechanism and characterization of graphene nanosheets dispersed at various concentrations of polar solvents (isopropanol, IPA) to improve the conductivity of the nanohybrids are evaluated using scanning electron microscopy (SEM), atomic force microscopy (AFM), X-ray diffraction (XRD), four-point probe sheet resistance measurements, and UV/vis spectroscopy. The results show that the conductivity of the graphene/PEDOT:PSS nanohybrids significantly improves upon addition of 50 wt.% IPA (the optimum conditions). The sheet resistance of the nanohybrids was reduced by ~ 95% from 16.6 kΩ/□ by addition of 0 wt.% IPA to 0.85 kΩ/□ by addition of 50 wt.% IPA, whereas the transparency still remained up to 82%. The conductivity could then be rapidly enhanced (from 0.85 kΩ/□ to 0.64 kΩ/□) by a second treatment of H2SO4, with a concomitant loss of transmittance. The correlations among the roughness, hydrophilicity, conductivity, and transparency also are investigated in detail in this paper. It is anticipated that graphene/PEDOT:PSS nanohybrids can be potentially used in an electronic and biomedical platform, such as biosensors.

Magnetic sensitive hydrogels (ferrogels) with tunable nanochannels were prepared with poly (vinyl alcohol) (PVA) and iron oxide magnetic nanoparticles under a uniform magnetic field in a freezing–thawing process, evaluated by differential scanning calorimetry (DSC), and the influence of magnetic nanoparticle arrangement on the diffusion behavior of biomolecules was investigated. Nanochannels self-assembled by the arranged magnetic nanoparticles could be tuned by manipulating the direction of the magnetic field, which results in the formation of “needle-like” structures from the magnetic nanoparticles aligned parallel or perpendicular to the permeation direction (anisotropic ferrogels). The effect of biomolecule diffusion between the anisotropic and isotropic ferrogels was observed in a diffusion diaphragm cell (using random nanoparticle dispersions without a magnetic field, as a control). It was established that the parallel-aligned ferrogels exhibit a higher drug diffusion rate compared to the isotropic ferrogels, whereas the perpendicular-aligned ferrogels display the lowest biomolecule diffusion rate. The novel ferrogels were expected to be suitable for application in bio-membranes, and the nanochannels for biomolecule (MW: ca. 0.1–10 kDa) diffusion could be constructed precisely by the magnetic nanoparticle arrangement.

Gold nanoparticles bound with inositol hexaphosphate (IP6) (AuNPs/IP6) were prepared byin situreduction of various concentrations of IP6(0~320 µM) through modified Frens method for surface-enhanced Raman scattering (SERS) detection. The resultant AuNPs/IP6were subject to characterization including UV/Vis spectroscopy, transmission electron microscopy (TEM), dynamic light scattering (DLS), zeta potential, and X-ray photoelectron spectroscopy (XPS). The results showed that AuNPs with 65 µM of IP6would result in a core AuNPs-shell (IP6layer) structure, which exhibited the strongest SERS signal, due to the “hot spot effect” generated from the 1-2 nm interparticle gaps of AuNPs/IP6nanohybrids (ionic interaction of IP6and Au+). Furthermore, the reaction kinetics of Au and IP6were also investigated in this work. Higher concentration of IP6(190 and 260 µM) will make AuNPs become irregularly shaped, because IP6is a basic salt and served as a pH mediator. The morphology and distribution of AuNPs were greatly improved by addition of 65 µM of IP6. This novel AuNPs/IP6nanohybrid showed great stability and Raman enhancement. It is promising in the application of rapid and label-free biological detection of bacteria or tumor cells.

Magnetically and thermally sensitive poly(N-isopropylacrylamide) (PNIPAAm)/Fe(3)O(4)-NH(2) microgels with the encapsulated anti-cancer drug curcumin (Cur) were designed and fabricated for magnetically triggered release. PNIPAAm-based magnetic microgels with a spherical structure were produced via a temperature-induced emulsion followed with physical-crosslinking by mixing PNIPAAm, polyethylenimine (PEI), and Fe(3)O(4)-NH(2) magnetic nanoparticles. Because of their dispersity, the Fe(3)O(4)-NH(2) nanoparticles were embedded inside the polymer matrix. The amine groups exposed on the Fe(3)O(4)-NH(2) and PEI surface supported the spherical structure by physically crosslinking with the amide groups of the PNIPAAm. The hydrophobic anti-cancer drug curcumin can be dispersed in water after encapsulation into the microgels. The microgels were characterized by transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FT-IR), and UV-Vis spectral analysis. Furthermore, magnetically triggered release was studied under an external high frequency magnetic field (HFMF). A significant "burst release" of curcumin was observed after applying the HFMF to the microgels due to the magnetic inductive heating (hyperthermia) effect. This manuscript describes the magnetically triggered controlled release of Cur-PNIPAAm/Fe(3)O(4)-NH(2) encapsulated curcumin, which can be potentially applied for tumor therapy.

Magnetically and thermally sensitive poly(N-isopropylacrylamide) (PNIPAAm)/Fe3O4-NH2 microgels with the encapsulated anti-cancer drug curcumin (Cur) were designed and fabricated for magnetically triggered release. PNIPAAm-based magnetic microgels with a spherical structure were produced via a temperature-induced emulsion followed with physical-crosslinking by mixing PNIPAAm, polyethylenimine (PEI), and Fe3O4-NH2 magnetic nanoparticles. Because of their dispersity, the Fe3O4-NH2 nanoparticles were embedded inside the polymer matrix. The amine groups exposed on the Fe3O4-NH2 and PEI surface supported the spherical structure by physically crosslinking with the amide groups of the PNIPAAm. The hydrophobic anti-cancer drug curcumin can be dispersed in water after encapsulation into the microgels. The microgels were characterized by transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FT-IR), and UV-Vis spectral analysis. Furthermore, magnetically triggered release was studied under an external high frequency magnetic field (HFMF). A significant "burst release" of curcumin was observed after applying the HFMF to the microgels due to the magnetic inductive heating (hyperthermia) effect. This manuscript describes the magnetically triggered controlled release of Cur-PNIPAAm/Fe3O4-NH2 encapsulated curcumin, which can be potentially applied for tumor therapy.

We have successfully produced bimetallic PtNi alloy nanoparticles on poly(diallyldimethylammonium chloride) (PDDA)-modified graphene nanosheets (PtNi/PDDA-G) by the “one-pot” hydrothermal method. The size of PtNi alloy nanoparticles is approximately 2–5 nm. The PDDA-modified graphene nanosheets (PDDA-G) provides an anchored site for metal precursors; hence, the PtNi nanoparticles could be easily bond on the PDDA-G substrate. PtNi alloy nanoparticles (2–5 nm) display a homogenous alloy phase embedded on the PDDA-G substrate, evaluated by Raman, X-ray diffractometer (XRD), thermal gravity analysis (TGA), electron surface chemical analysis (ESCA), and electron energy loss spectroscopy (EELS). The Pt/Ni ratio of PtNi alloy nanoparticles is ~1.7, examined by the energy dispersive spectroscopy (EDS) spectra of transmitting electron microscopy (EDS/TEM spectra) and mapping technique. The methanol electro-oxidation of PtNi/PDDA-G was evaluated by cyclic voltammetry (CV) in 0.5 M of H2SO4 and 0.5 M of CH3OH. Compared to Pt on carbon nanoparticles (Pt/C) and Pt on Graphene (Pt/G), the PtNi/PDDA-G exhibits the optimal electrochemical surface area (ECSA), methanol oxidation reaction (MOR) activity, and durability by chrono amperometry (CA) test, which can be a candidate for MOR in the electro-catalysis of direct methanol fuel cells (DMFC).

In this research, graphene nanosheets were functionalized with cationic poly (diallyldimethylammonium chloride) (PDDA) and citrate-capped gold nanoparticles (AuNPs) for surface-enhanced Raman scattering (SERS) bio-detection application. AuNPs were synthesized by the traditional citrate thermal reduction method and then adsorbed onto graphene-PDDA nanohybrid sheets with electrostatic interaction. The nanohybrids were subject to characterization including X-ray diffraction (XRD), transmission electron microscopy (TEM), zeta potential, and X-ray photoelectron spectroscopy (XPS). The results showed that the diameter of AuNPs is about 15-20 nm immobilized on the graphene-PDDA sheets, and the zeta potential of various AuNPs/graphene-PDDA ratio is 7.7-38.4 mV. Furthermore, the resulting nanohybrids of AuNPs/graphene-PDDA were used for SERS detection of small molecules (adenine) and microorganisms (Staphylococcus aureus), by varying the ratios between AuNPs and graphene-PDDA. AuNPs/graphene-PDDA in the ratio of AuNPs/graphene-PDDA = 4:1 exhibited the strongest SERS signal in SERS detection of adenine and S. aureus. Thus, it is promising in the application of rapid and label-free bio-detection of bacteria or tumor cells.