This PDF file contains the front matter associated with SPIE Proceedings Volume 7765, including the Title Page, Copyright information, Table of Contents, Introduction, and the Conference Committee listing.

In this paper we present our current research in developing non-conductive, optically transparent electromagnetic interference (EMI) or radio frequency (RF) shielding. It uses metallic nanopowders blended with deoxyribonucleic acid (DNA) based host materials. Recent results of this DNA-based EMI shielding demonstrate 18-27dB over a frequency range of 18 - 6 GHz, respectively, with an electrical resistivity measuring > 20MΩ for a 20 μm dielectric spacing. These films were optical transparent in the visible wavelength range.

Interactions with double strand structure of DNA enhance or modify the optical characteristics of organic dyes through its influences on electronic and structural properties. We investigated the absorption and emission spectra of several types of water soluble cyanine dyes, showing that the quite low concentration of DNA has large effects on the aggregate behaviors of the dyes in solutions and complex films. This effect was applied to control the J-aggregate formation of pseudo-isocyanine dye, demonstrating the J-aggregate spectra in solutions and polymer films with rather low concentration of the dyes. These results were important for realization of novel optical devices such as solid state dye laser and nonlinear optical switches incorporating DNA and other relating materials.

We use the recently formulated hypothesis of semi-intercalation of an azo-dye Disperse Red 1 (DR1) into a biopolymeric material made of deoxyribonucleic acid (DNA) complexed with the cationic surfactant hexadecyltrimethylammonium chloride (CTMA)^1-3 to model the unique photochromic properties of the DR1:DNA-CTMA system. First results of kinetic Monte Carlo simulations accurately reproduce4 the main experimental results5 of laser dynamic inscription of diffraction gratings in this photochromic material: short response time, low diffraction efficiency, single-exponential kinetics and flat wavelength dependence. Results of systematic MC studies are presented. The question of extending the model of paper4 by including into it probabilistic features of local free volume in DNA matrix is discussed.

DNA, a biopolymer processed from purified marine-based waste products, has been explored in recent years for photonic applications. Among these, using a DNA-surfactant biopolymer as a conductive cladding layer in electro-optic polymer waveguide modulators has been proposed due to the biopolymer's low optical loss and relatively high electrical conductivity compared to current polymer materials. Electric-field contact poling measurements using a DNA-surfactant biopolymer as a cladding layer have been made. The DNA cladding layer yielded high poling efficiency and the results are reported here.

DNA-CTMA or DNA-CTMA-PMMA films have been studied as a potential material for waveguide type thin-film photonic devices such as dye-doped thin film lasers, optical waveguide amplifiers, or optical waveguide switches. For the purpose of evaluate processability, not only optical characteristics of the fluorescence intensity but also moisture resistance of the film have been investigated. It is found that optical characteristics of those films are equally matched to the conventional DNA-CTMA films with better moisture resistivity. Waveguide fabrication experiments by using DNA-CTMA-PMMA films showed good moisture resistant nature and processability.

We present results of the amplified spontaneous emission (ASE) in the system based on dye-doped modified DNACTMA (deoxyribonucleic acid with cetyltrimethyl-ammonium chloride) and lasing in distributed feedback Bragg (DFB) laser composed of a two-layer system: a layer of modified (DNA) polymeric matrix containing dye superimposed on a periodic relief structure formed in photochromic polymer layer. As photoactive and luminescent dye we used the wellknown Rhodamine (Rh 6G). This layer covered a specially designed photochromic polymer layer in which a surface relief grating (SRG) was inscribed by holographic method in order to form a Bragg reflector for photons. Thin film of the DNA-CTMA:Rh6G/photochromic polymer was excited with 6 nanosecond laser pulses at λ = 532 nm wavelength.

Crosslinking reactions of DNA film by UV irradiation were investigated in terms of structural changes which indicated the formation of -O-P-O- bond. The UV-cured DNA films were applied to medical uses for cell culture and wound-healing of skin, which were very effective for medical applications.

The processing, fabrication and measurement of resistivity devices using salmon-derived DNA are reviewed in some detail. Details of the current transients that are recorded during the alternating-polarity technique are examined and identified. The DC volume resistivities of both as-received DNA and DNA-CTMA as well as the resistivity dependence on the molecular weight of DNA(sonicated)-CTMA are reviewed, which includes an analysis of this dependence and the effects of humidity on the measurements. Using the Miller-Abrahams model for hopping conduction provides insight into the relative sizes of the pre-exponential factors of the Arrhenius functions for the resistivity data of a variety of oil-derived polymers, and DNA and silk biopolymers.

In this paper we investigate the electrical properties of DNA-PEDOT blends, with particular interest as semiconducting materials in thin film based Field Effect Transistors (FET) applications. We report the template polymerization of poly(3,4-ethylenedioxythiophene) (PEDOT) using a biomacromolecule, DNA, as the polyelectrolyte. The obtained biocomposite stability is very dependent on the type of oxidant used in the chemical synthesis route. The resultant polymer system is water processable and undergoes the same redox processes as PEDOT alone. Films with thicknesses of 0.5 to 1 microns were drop cast from water based solution using different ratios EDOT to DNA.

We demonstrated green to red color-tunable OLED based on DNA/PAn/Ru(bpy)3 ²⁺ complex (hole transport layer) and tris(8-hydroxyquinolinato)aluminium (Alq3: electron transport layer). The emission color of the OLED was controlled by applied voltage. At low applied voltage, the green emission dominated by Alq3 was observed. The emission color was changed from green, yellow to red with a strong contribution of red emission of Ru(bpy)3 ²⁺ as voltage increased. This multi color emission phenomenon would be attributed to the shift of the carrier recombination zone depending on applied voltage.

We investigate the dielectric and electrical properties of sol-gel/DNA-CTMA blends, with particular interest in capacitor applications in energy storage. Methacryloyloxypropyltrimethoxysilane (MAPTMS) was the solgel precursor, and DNA-CTMA was blended in to the resulting sol-gel at various weight percentages. The blends were tested for their dielectric properties and dielectric breakdown strength; the 5% DNA blend was found to be optimal with a dielectric constant in the range of 7.5, while the breakdown strength was greater than 800 V/μm for 1 μm films and about 500 V/μm for 5μm films. Hybrid sol-gel/DNA-CTMA/barium titanate nanoparticle composites were also formulated and their dielectric properties measured. While a high dielectric constant was achieved (38), this came at the expense of a significantly reduced breakdown voltage (160V/μm). We discuss these results as well as other aspects of the dielectric and electrical properties of these blends.

The second-order nonlinear optical properties of a number of fluorescent proteins (FPs) (green, EGFP; yellow, EYFP and zFP538; red, DsRed, mStrawberry and mCherry) have been determined by frequency-resolved femtosecond hyper- Rayleigh scattering. In general, the more red-shifted the absorption and emission wavelength are, the larger the intrinsic, resonance-free, first hyperpolarizability is. The anomalously low first hyperpolarizability for the yellow EYFP variant had been rationalized in terms of the centrosymmetrical stacking between a phenolic residue and the tyrosine chromophoric moiety, leaving as effective non-centrosymmetric chromophore for second-order nonlinear effects only the small imidazolinone moiety. This has now been confirmed by the higher hyperpolarizability, in line with the observed trend from the EGFP benchmark to the more red-shifted FPs, which is observed for the yellow zFP538 variant exhibiting similar stacking yet with a histidine moiety, precluding the centrosymmetry effect.

Organic electro-optic materials have potential applications in optical communication and data processing. One major obstacle to the realization of the full potential of OEO materials is the interchromophore electrostatic interactions which have prevented the poling-induced chromophore order parameter from reaching above 0.3. In this presentation, we show designs of new chromophores that have ring structures surrounding the center of chromophores to prevent chromophores from packing in the antiparallel fashion, and modification of such chromophores with complementary DNA nucleobases to strengthen head-tail interactions.

Biomaterials such as nucleic acids and proteins can be exploited to create higher order structures. The biomolecular components such as DNA and peptides have been used to assemble nanoparticles with high fidelity. Here, we use DNA and peptides, and their preferential interaction with inorganic and carbon nanomaterials to form homogeneous hybrids. The enhanced binding of Pt ions to both DNA and peptide functionalized nanoparticles mediates the assembly of carbon nanotubes functionalized with DNA with peptide coated gold nanoparticles.

DNA has attracted much interest as a material for nano science and technology. To unveil the intrinsic nature of DNA both in natural form and modified forms of M-DNA with a variety of divalent metal ions. From the magnetic and optical properties, it is concluded that the electronic states of natural salmon DNA is of semiconducting. Thus, only the hopping transport via excited states or impurity site like oxygens is expected. One of the efforts to introduce charge carriers into DNA, insertion of divalent metal ions, has been studied from magnetic, optical and structural aspects. It was concluded that the divalent metal ions are inserted in between the bases of a base pair, in place of hydrogen bonds, and the charge transfer from the metal ions to DNA occurs only in the case of Fe-DNA.

Unlike conventional multiphoton excited microscopy according to pixel-by-pixel point scanning, a widefield multiphoton excited microscopy based on spatiotemporal focusing has been developed to construct three-dimensional (3D) multiphoton fluorescence images only with the need of an axial scanning. By implementing a 4.0 W 10 kHz femtosecond laser amplifier with an instant strong peak power and a fast TE-cooled EMCCD camera with an ultra-sensitive fluorescence detection, the multiphoton excited fluorescence images with the excitation area over 100 μm x 100 μm can be achieved at a frame rate up to 80 Hz. A mechanical shutter is utilized to control the exposure time of 1 ms, i.e. average ten laser pulses reach the fluorescent specimen, and hence an uniform enough multiphoton excited fluorescence image can be attained with less photobleaching. The Brownian motion of microbeads and 3D neuron cells of a rat cerebellum have been observed with a lateral spatial resolution of 0.24 μm and an axial resolution of 2.5 μm. Therefore, the developed widefield multiphoton microscopy can provide fast and high-resolution multiphoton excited fluorescence images for animal study in vivo.