The emerging demand for device miniaturization and integration prompts the patterning technique of micronano-cross-scale structures as an urgent desire. Lithography, as a sufficient patterning technique, has been playing an important role in achieving functional micronanoscale structures for decades. As a promising alternative, we have proposed and demonstrated the maskless optical projection nanolithography (MLOP-NL) technique for efficient cross-scale patterning.
View Article and Find Full Text PDFThe biocompatibility of the three-dimensional (3D) hydrogel cell scaffolds that sodium hyaluronate (SH) and carboxymethyl chitosan (Chitosan) has been investigated. The minimum processing threshold of 2.94 mW and the feature line width of 80 nm have been obtained by the two-photon polymerization (TPP) technology using the as-prepared biocompatible photoresist.
View Article and Find Full Text PDFWe have introduced a novel water-soluble two-photon photoinitiator based on the host-guest interaction between 3,6-bis[2-(1-methyl-pyridinium)vinyl]-9-pentyl-carbazole diiodide (BMVPC) and cucurbit[7]uril (CB7) because most of the commercial photoinitiators have poor two-photon initiating efficiency in aqueous solutions. The binding ratio of BMVPC and CB7 was determined as 1:1 by isothermal titration calorimetry and quantum chemical calculation. The formation of the host-guest complex increases the two-photon absorption cross-section about five times, and improves the water solubility required as the photoinitiator for hydrogel fabrication.
View Article and Find Full Text PDFAccurate knowledge of electrical conductivity and thermal conductivity temperature dependence plays a crucial role in the design of a thermometer. Here, by using a two-beam laser direct writing system, an individual silver nanowire (AgNW) with well-defined dimensions is fabricated on a polyethylene terephthalate (PET) substrate. The temperature dependence of the resistivity of the fabricated AgNW is measured ranging from 10 to 300 K, and fitted with the Bloch-Grüneisen formula.
View Article and Find Full Text PDFFlexible electrically conductive nanowires are now a key component in the fields of flexible devices. The achievement of metal nanowire with good flexibility, conductivity, compact and smooth morphology is recognized as one critical milestone for the flexible devices. In this study, a two-beam laser direct writing system is designed to fabricate AgNW on PET sheet.
View Article and Find Full Text PDFNanodiamond, which has a lattice defect, the energy band gap and good biocompatibility, is an ideal inorganic fluorescent imaging material for cells. However, the nanodiamond aggregation is not exactly suitable for cells' endocytosis if the size is too small or too big. Therefore, it has a profound meaning to modify the surface of nanodiamond and control the dispersion of nanodiamond aggregate.
View Article and Find Full Text PDFWe demonstrate the transition of lasing modes in the resonating cavity constructed by polystyrene opal photonic crystals and 7 wt. % tert-butyl Rhodamine B doped polymer film. Both single mode and multiple mode lasing emission are observed from the resonating cavity.
View Article and Find Full Text PDFWe demonstrate low threshold lasing oscillation in a photonic crystal (PhC) laser by using tert-butyl Rhodamine B (t-Bu-RhB) doped gain media. Lactonic t-Bu-RhB is synthesized to improve doping concentration in polymethylmethacrylate (PMMA) films, and then isomerized to the zwitterion form to achieve highly fluorescent gain medium. The t-Bu-RhB doped PMMA film is sandwiched by a pair of polystyrene colloidal crystals to construct a PhC resonating cavity.
View Article and Find Full Text PDFWe describe how the transformation-optics technique can be used to design an effective medium mimicking the conical curvature singularity. Anholonomic coordinate transformation gives rise to linear topological defects that break the rotational symmetry. The bending and splitting of the optical beams are found analytically and numerically, depending on the incident direction and the topological charge.
View Article and Find Full Text PDFHere, we have introduced a novel biscarbazolylmethane-based cyanine as a two-photon excited fluorescent probe, 6,6'-bis[2-(1-methylpyridinium)vinyl]-bis(9-methyl-carbazol-3-yl)methane diiodide, which has two vinylpyridinium carbazole moieties connected by a non-rigid methylene bridge. This molecule possesses a larger Stokes shift and enhanced two-photon absorption cross-section than the previously reported vinylpyridinium carbazole monocyanine, which is mainly attributed to the "through-space" type intramolecular charge transfer. The low fluorescence quantum yield and 30-fold fluorescence enhancement once binding with calf thymus DNA highlight this molecule as a promising fluorescence light-up probe for DNA.
View Article and Find Full Text PDFWe have investigated the photoinitiating properties of the photoinitiator 3,6-bis[2-(4-nitrophenyl)-ethynyl]-9-(4-methoxy-benzyl)-carbazole (BNMBC), which has an intramolecular radical quenching group "p-methoxybenzyl," in the substrate lines fabrication of two-photon induced photopolymerization (TPIP). Another photoinitiator 3,6-bis[2-(4-nitrophenyl)-ethynyl]-9-benzyl-carbazole (BNBC) with similar chemical structure but not radical quenching group was studied for comparison. Their photopolymerization properties were studied with resins in which BNBC and BNMBC were used as photoinitiators with a molar ratio of 0.
View Article and Find Full Text PDFScreening the anticoccidial drug targets is very important for developing novel drugs and revealing the molecular basis of drug resistance in coccidia. Due to high effectivity and safety, diclazuril was used widely in the poultry industry. To assess the roles of the serine/threonine protein phosphatase type 5 of second-generation merozoites in Eimeria tenella (EtPP5) in the anticoccidial activity of diclazuril against chicken coccidiosis, EtPP5 was cloned using reverse transcriptase polymerase chain reaction and rapid amplification of cDNA ends.
View Article and Find Full Text PDFA series of C(2v) symmetrical two-photon absorption compounds with anthracene core, 2,7-bis[2-(4-substituted phenyl)-vinyl]-9,10-dipentyloxyanthracenes designated as I, II and III (the substituted groups at the 4-position of phenyl of I, II and III were dimethylamino, methyl and cyano, respectively) were designed and synthesized as initiators in two-photon induced polymerization (TPIP). The anthracene ring was modified by linking vinylphenyl groups to the 2,7-position to extend conjugation system length and two pentyloxy groups to the 9,10-position to serve as electronic donors. Two-photon absorption cross section of I was around 300 GM, which was much larger than the 10 GM of II and 29 GM of III at 800 nm.
View Article and Find Full Text PDFPhys Chem Chem Phys
October 2012
The synthesis of hybrid nanostructures with controlled size, shape, composition and morphology has attracted increasing attention due to the fundamental and applicable interest. Here, we demonstrate the synthesis and optical properties of hierarchical CdSe-Au hybrid nanostructures with zinc blende (ZB) CdSe nanocrystals (NCs). For 3.
View Article and Find Full Text PDFWe have successfully prepared gold nanoparticles (AuNPs) with flower-like and spherical morphology through multi-photon photoreduction (MPR) of an aqueous solution of HAuCl(4) and (2-hydroxyethyl) trimethylammonium glycinate ([HETMA][Gly]) ionic liquid (IL) through the use of a femtosecond laser. The results of (1)H NMR and UV-Vis absorption indicated that AuNPs were produced from the photoreduction of the [Gly]-Au(iii) complex. Spherical AuNPs of about 2.
View Article and Find Full Text PDFWe investigate the optical properties of mono- and double-layer asymmetric fishnet metamaterials with orientated elliptical holes, which exhibit exotic spectral and polarization rotating characteristics in the visible spectral range. Our results show that nontrivial orientations of the holes with respect to the reciprocal lattice vectors of the periodic lattice in both systems produce strong polarization rotation as well as additional enhanced optical transmission peaks. Analysis of the electromagnetic field distribution shows the unusual effect is produced by the spinning localized surface plasmon resonances due to the asymmetric geometry.
View Article and Find Full Text PDFJ Nanosci Nanotechnol
October 2011
We have investigated the morphology modification of silver microstructures fabricated by the multiphoton photoreduction process. The microstructures have been fabricated by a femtosecond laser under different irradiation time and repeated scanning numbers. Trans-4-[4-(dimethylamino)-N-methylstilbazolium] p-tosylate (DAST) was used as photosensitizer and effectively reduced the laser power to 0.
View Article and Find Full Text PDFUnlabelled: Prenatal exposure to LPS(lipopolysaccharide) results in renal damage in offspring rats, but the mechanism is unknown. The present study was to explore the role of angiotensin II and inflammation in the development of renal damage induced by prenatal exposure to LPS. The pregnant rats were randomly divided into two groups, i.
View Article and Find Full Text PDFWe designed, fabricated and characterized a nano-periodical highly-efficient blazed grating for extreme-ultraviolet (XUV) radiation. The grating was optimized by the rigorous coupled-wave analysis method (RCWA) and milled into the top layer of a highly-reflective mirror for IR light. The XUV diffraction efficiency was determined to be around 20% in the range from 35.
View Article and Find Full Text PDFGold nanoparticles (AuNP's) prepared through a controllable synthesis and aggregation process are attractive for their unique properties that arise from their surface plasmon resonances (SPRs). However, aggregation-controlled AuNP's on amorphous surfaces have not been well explored. In this study, we present a simple in situ synthesis method for preparing AuNP's in which the AuNP's self-aggregate into microscale Candock-leaf-like structures on a polyelectrolyte film (PEF) surface.
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