Mass spectrometric imaging (MSI) is a powerful method using nanoparticles for detecting a substance to clarify the biological tissue and its distribution. MSI has attracted a lot of attention for drug development, for investigation of pathology biomedical research applications. We have developed this technique by nanoparticle-assisted laser desorption / ionization mass spectrometry. In this report, we have focused on Methyl 2-Octynoate (2-OA), because this substance is said to be involved in the development of Primary Biliary Cirrhosis (PBC) which is known as a liver disease specifically appeared in female. We prepared the functional iron oxide nanoparticles, and performed MSI for the mouse liver sections after the administration of 2-OA. We have concluded that our developed functional nanoparticles was effective for identifying the adsorbed analytes on the living cell. Our proposed would contribute to the development of the medical field.
This study reports the synthesis of size-controlled MFI-type ferrisilicates (Fe-MFI, Fe-substituted zeolites with the MFI topology) and their catalytic performances for DTO (dimethyl ether-to-olefins) reaction. The amount of HCl in precursor solution and aging temperature were decisive factors to control the particle size of Fe-MFI in the range of 50 nm to 600 nm. The introduction of Fe3+ ions into the zeolitic framework was confirmed by UV-visible spectroscopy. In addition, it was observed that the strength of acid site in prepared Fe-MFI was weaker than that of ZSM-5. With decrease in the particle size, the rate of coke deposition decreased so that the catalyst life for the DTO reaction was well promoted.
We report herein a development of flexible enzyme electrodes and a completely organic iontophoresis patch integrated with the biofuel cell. The enzyme electrodes are composed of carbon nanotube-modified flexible carbon fabrics and enzymatic catalysts. An assembled flexible biofuel cell produced a maximum power density of 0.7 mW/ cm2 and a maximum current density of 2.0 mA/cm2, respectively. Such flexible biofuel cell could be integrated into an iontophoresis patch, resulting in generating transdermal iontophoretic administration of compounds into the skin via ionic current through the skin.
Irradiation of visible and/or near-infrared light on metal nanostructures induces collective oscillation of the surface conduction electrons, which is localized surface plasmon (LSP). Strong interaction between LSP and excitons of molecules is called strong coupling and hybridized states are formed. In this study, we adsorbed dye molecules on Ag nano structures and led to the formation of strong coupling regime. Spatial distribution of strong coupling between LSP and dye molecule exciton was characterized by the dark field scattering imaging spectroscopy under electrochemical potential control. The states of the coupling were tuned by the control of the LSP energies and the number of dye molecule via electrochemical potential control of the system. The spatial distribution of the coupling strength was analyzed by scattering images and scattering spectra. We propose our present method as a novel idea to characterize strong coupling states under electrochemical potential control.
Delafossite Silver Iron oxides AgFeO2 are expected to be widely used in future applications such as dilute magnetic semiconductors (DMSs) and multiferroic materials. AgFe1-xCoxO2 (0 ≤ x ≤ 0.3) nanoparticles were synthesized by co-precipitation from silver nitrate, iron (III) nitrate, cobalt (II) nitrate and sodium hydroxide. The resulting samples had an estimated particle size of around 10 nm, and were subsequently analyzed by X-ray powder diffraction (XRD), TEM imaging, and X-ray absorption fine structure (XAFS) measurement. This found that the axis of the lattice constants decreased with increasing Co-ion doping, with the XAFS spectra revealing that Fe and Co ions mainly exist as trivalent Fe3+ and Co3+. Measurement of the magnetic properties by a SQUID magnetometer identified a gradual shift in the magnetic transition temperature (TN1) from 15 to 11.2 K as the Co-ion doping was increased.
I-III-VI2 ternary semiconductors are an important class of materials with wide applications from optelectronic devices to photocatalytic energy conversion. Among them, non-toxic and highly cost-effective CuInS2 is a striking material attracting the numerous attentions due to the potential applications in highly-efficient solar cells. The study on the relationship between photo-induced carrier dynamics and structures of CuInS2 nanocrystals (NCs) including shapes, sizes, and protecting ligand is an important guideline for developing the exquisite structure suiting for the applications. However, the direct observations of the photo-induced carrier dynamics of CuInS2 NCs using the laser flash photolysis (LFP) are still rare. In the present study, we successfully synthesized the typical oleylamineprotected CuInS2 NCs (CuInS2 nanoparticles (NPs) and nanodisks (NDs)) and photo-induced carrier dynamics of oleylamine-protected CuInS2 NPs and NDs were investigated through the transient absorption measurement. The decay of laser induced excitons in the NCs was not sensitive to the crystal structure nor shape of the CuInS2 NCs but significantly affected by defect trapping and/or energy transfer to the hole-based localized surface plasmon resonances in the NCs. Our results indicate that careful selection of protecting ligand is essential to obtain CuInS2NCs with optimized optical properties for specific applications.
Liquid-crystalline (LC) organic dendron is one of the most representatives to form spherical dendrimer-like structures by the self-assembling property. Such spherical assembly spontaneously forms a self-organized periodical structure. Thus, we focused our attention on introduction of such self-organization ability into inorganic NPs. As the result, we have recently developed LC organic-inorganic hybrid dendrimers with a spherical nanoparticle (NP) at its core. Dense surface modification of the NPs with LC dendrons was found to exhibit a thermotropic LC phase with simple cubic structures. In the present study, rheological behavior of the dendron-modified gold NPs was carried out to investigate the effect of modification amount of the dendrons on the LC behavior.