This PDF file contains the front matter associated with SPIE Proceedings Volume 7403, including the Title Page, Copyright information, Table of Contents, Introduction (if any), and the Conference Committee listing.

Quantum dots have been shown to provide a particularly effective approach to bright nano-objects for bioimaging due to their unique optical properties, including their robust and size-dependent fluorescence. However these "hard" nanoparticles raised a number of questions related to toxicity, biocompatibility and/or environmental issues. In that context, we have developed a new class of "soft" fully organic alternative nanoparticles (i.e. organic nanodots). Our approach relies on the confinement of a large number of organic chromophores within spherical nano-objects of controlled size and structure, by embedding them within non-toxic and biocompatible dendrimeric architectures. This highly modular strategy yielded organic nanodots of different sizes, colors and nature (lipophilic and hydrophilic). In contrast with quantum dots (QDs), their emission color does not depend on their size, but only on the nature of their constituting chromophoric subunits and their relative arrangement. Several series of nanodots of few nanometers in diameter have been studied, exhibiting exceptional one and two-photon brightness and often outperforming the best quantum dots. Nanodots offer major promises for bio and nanophotonics.

The construction of efficient light energy converting (photovoltaic and photo-electronic) devices is a current and great challenge in science and technology and one that will have important economic consequences. Several innovative nanoelectronic materials were proposed to achieve this goal, semiconductor quantum dots, metallic nanowires and carbon nanotubes (CNT) are among them. As a charge separating unit for light energy conversion, we propose the utilization of the most advanced photoelectronic material developed by nature, photosynthetic reaction center proteins. As a first step in this direction, we constructed a novel bioinorganic nanophotoelectronic material with photoactive photosynthetic reaction center (RC) proteins encapsulated inside a multiwall CNT arrayed electrode. The material consists of photosynthetic RC-cytochrome complexes acting as charge separating units bound to the inner walls of a CNT electrode and ubiquinone-10 (Q2) serving as a soluble electron-transfer mediator to the counter electrode. The proteins were immobilized inside carbon nanotubes by a Ni(NTA)-alkane-pyrene linker, forming a self-assembled monolayer (SAM) on the surface of inner CNT walls and allowing for unidirectional protein orientation. The material demonstrates an enhanced photoinduced electron transfer rate and shows substantial improvement in photocurrent density compared to that obtained with the same proteins when immobilized on planar graphite (HOPG) electrode. The results suggest that protein encapsulation in precisely organized arrayed tubular electrode architecture can considerably improve the performance of photovoltaic, photoelectronic, or biofuel cell devices. They demonstrate the potential for substantial advantages of precisely organized nano electrode tubular arrayed architecture for variety biotechnological applications.

This paper describes preparations of innovative photonic devices based on high purity DNA molecules which are obtained from Salmon roe. DNA molecules have characteristic features of double helical chain structures where aromatic compounds can intercalate into the stacked layers so that various optically active aromatic dyes indicate strong enhancement effects of photonic activities. Thus, various DNA photonic devices have been developed in the world in terms of optical switches, electro-luminescence (EL), lasers and so on. However, these DNA photonic devices adsorb moisture in the air because of hydrophilic character of DNA molecules, leading to decrease photonic activities. Nevertheless, it was found by my group that a novel hybridization method of the dye-intercalated DNA molecules by means of so-called so-gel process increased stabilities and durability of DNA photonic devices under environmental changes. Also, hybridization of dye-intercalated DNA devices with synthetic polymers including fluorinated poly(methylmethacrylate ) or polycarbonates was successfully carried out by solution blending method, followed by casting the solution to obtain these films which showed stability and durability increases of these DNA photonic devices. DNA-lipid complexes showed a very strong fluorescence amplification by chelating with rare earth metals such as Europium or Telbiumu compounds. This paper also describes the chelate effects of rare earth metal compounds for light amplifications.

Ordered DNA - silica materials have been efficiently synthesized by using the microemulsion sol - gel procedure. Dynamic Light Scattering (DLS) spectra showed that the microemulsion systems applied for DNA - silica materials synthesis contain structural units similar in size and shape. The atomic force microscopy (AFM) analysis revealed that the obtained DNA - silica thin films exhibit an ordered units array pattern structure in micron scale and the structural units channels run parallel with each. The UV - VIS reflectance spectra performed for DNA/Rhodamine - silica materials proved that the structure and properties of native DNA are protected by incorporation. The obtained results assumed a globular shape of the DNA imposed by microemulsion template and the chromophore location into its double helix structure. An improvement of the thermal properties of DNA, incorporated into the DNA - silica material, was observed by the thermogravimetric-differential thermal analysis (TGA-DTA).

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 sol-gel precursor, and DNA-CTMA was blended in to the resulting sol-gel at 5 weight%. The blend was then tested for its dielectric properties and dielectric breakdown strength; at frequencies below 10kHz the blend was found to have a dielectric constant in the range of 7.5, while the breakdown strength was greater than 800 V/μm, an exceptional value. We discuss these results as well as other aspects of the dielectric and electrical properties of these blends.

We report experimental observations and theoretical modeling of an unusual photoelectric effect in deoxyribonucleic acid (DNA) thin-film devices, under visible and near-infrared illumination. The devices also show diode-type rectifying current-voltage (I-V) characteristics. An equivalent circuit model was constructed that fits the experimental data, and physical processes likely to arise in the devices are discussed. We envisage the formation of a Schottky barrier at the DNA film-metal interface and infer that the photoresponse arises from photoinjection of electrons from the metal into the DNA film.

Single strand DNA (ss-DNA) fragments act as negative potential gating agents that increase the hole density in graphene. Patterning of biomolecules on graphene could provide new avenues to modulate the electrical properties. Current-voltage characterization of this hybrid ss-DNA / graphene system indicates a shift of the Dirac point and "intrinsic" conductance after ss-DNA is deposited. The effect of the ss-DNA is to increase the hole density in the graphene. The increased hole density is calculated to be 2 × 10¹² cm^-2. This increase is consistent with the Raman frequency shifts in the G peak and 2D band positions and the corresponding changes in the G-peak full-width half maximum. Ab initio calculations using density functional theory rule out significant charge transfer or modification of the graphene bandstructure in the presence of the ss-DNA fragments.

DNA/functional molecules such as (Ru(bpy)₃²⁺ complex, conducting polymer etc.) complex was prepared to study molecular structure and I-V characteristics towards DNA molecular wire. For example, Ru(bpy)₃²⁺ was associated with duplex of DNA by not only electrostatic interaction but also intercalation in the aqueous solution. Singlemolecular structure of DNA/Ru(bpy)₃²⁺ complex was analyzed with AFM. We found a network structure of DNA/Ru(bpy)₃²⁺ complex on the mica substrate, which is similar to native DNA. The height of DNA/Ru(bpy)₃²⁺ complex on the mica substrate was ranging from 0.8 to 1.6 nm, which was higher than the naked DNA (0.5-1.0 nm). This indicates that single-molecular DNA/Ru(bpy)₃²⁺ complex also connects to each other to form network structure on a mica substrate. In order to stretch DNA complex between electrodes, we employed high frequency and high electric field stretching method proposed by Washizu et al. We stretched and immobilized DNA single molecules between a pair of electrodes and its structures were analyzed with AFM technique. The I-V characteristics of DNA single molecules between electrodes were improved by the association of functional molecules with DNA. The molecular structure and I-V characteristics of DNA complex were discussed.

In this paper we report the latest results on DNA based field effect transistor. Blending DNA with either conductive polymers, carbon based nanoparticles or metal based compounds show an increase in surface conductivity and evidence of a field effect modulation of the drain-source currents.

We report an approach to produce predefined surface charge tunable gene delivery vectors using siloxysilsane-based polymer for gene delivery studies. To obtain nonviral vectors, new series of hyperbranched polysiloxysilane (HBPS) were synthesized, and the end groups in polymer structures have modified with hydrophilic molecules; in other words, carboxylic acid and quaternary ammonium groups were employed into terminal structures to give the amphiphilicity. The novelty of these amphiphilic HBPS polymers lies in the fact that nanoparticles with different zeta potential (surface charge density) can be easily tailored and functionalized. These polymeric nanoparticles which containing various chemical groups on the surface indicated altered surface charge distributions (from -40 to +64mV). Finally, the use of these nanoparticles as efficient gene delivery vectors was demonstrated by means of in vitro transfection study using β- galactosidase plasmid and pEGFP-N1 plasmid, and the most efficient combination was obtained using HBPS-CN30:70.

The nano crystalline hydroxyapatite with highly uniform spherical morphology has successfully been prepared using the new cationic surfactant Cetrimide as template by co-precipitation method at ambient temperature. The sample was calcinated at 750 °C for 8h. The FTIR spectrum shows the chemical composition of HAP. The XRD pattern confirms the characteristic peaks and the hexagonal structure of HAP. The lattice parameters calculated from the XRD pattern are a = b ~ 0.93873 nm, c = 0.68486 nm, the axial ratio ~0.7296, the volume of the unit cell ~522.6535x10-30 m3. The size and morphology of the sample were analyzed by FESEM, which shows that the spherical HAp particles with diameter 150-200 nm have successfully been synthesized. All the inspections confirm the successful preparation of nano spherical HAP with excellent morphology control, and uniform size.

DC resistivity studies were carried out on biopolymer films of DNA-CTMA and silk fibroin, and on selected traditional polymer films, including PMMA and APC. Films of DNA-CTMA versus molecular weight and with conductive dopants PCBM, BAYTRON P and ammonium tetrachloroplatinate are reported. The films were spin coated on glass slides configured for measurements of volume dc resistance. The measurements used the alternating polarity method to record the applied voltage-dependent current independent of charging and background currents. The Arrhenius equation plus a constant was fitted to the conductivity versus temperature data of the polymers and the non-doped DNA-based biopolymers with activation energies ranging from 0.8 to 1.4 eV.

Using a 4-f imaging system for nonlinear optical measurements we deal with multi-wave mixing experiments. The complex degenerate four-wave mixing experimental setup is simplified in order to characterize nonlinear materials. Moreover, a generalization of the I-scan method is studied by considering one, two, three and four waves mixing experiments. The determination of the cubic optical nonlinearity is possible by providing quadratic relations that relate the nonlinear phase shift to the measured signal. The sensitivities of the measurements are compared systematically showing the same order of magnitude for all the studied configurations. Experimental and simulated images are presented here to validate our approach.

The nonperturbative theory of the cooperative spontaneous emission from a two level atom trapped in one-dimensional damped nanocavity with a single resonance mode is presented. The time-dependent spectral properties and nonlinear dynamics of a separate photon emission by the macroolecular-like system "excited atom coupled to a resonance decaying mode" have been analyzed. The investigation has been carried out by solving the Schrödinger equation in the interaction picture with the help of the Green functions method in the Heitler-Ma's form . The formalism was supplemented with the novel algorithm in operating causal singular functions and with fundamentals of the theory of quantum quasi-stationary systems. The proposed theory accounts automatically of both reabsorptions of emitted photon and its simultaneous escaping out of the cavity. Solutions of the wave equation were found without using intermediate virtual states and series expansions. In accordance with the theory of quasistationary systems the field of mode decaying exponentially in the empty nanocavity was represented with the Lorenz-shaped packet of stationary photonic states (quasi-modes). The electro-dipolar interaction between the atom and the mode field was adopted to be switched on suddenly. The expressions and plots of emission spectral densities probabilities together with photon emission probability dynamics as functions of time for various ratios Γ/4g. For Γ/4g<1 the transient emission spectrum reveals the presence of two symmetrical side-bands and the central peak interconnected with each other in the area of interaction with the atom. Since the central component oscillates, decaying simultaneously in time at two rates infinity Γ/2 and ~ Γ/4, in the area of interaction the emission is a triplet with satellites oscillating in the interaction area and being stable outside of it. So the final spectrum is a doublet outside of nanocavity. On the contrary for Γ/4g ≥1 the spectrum is a singlet, and the emission occurs in exponentially decaying way.

and enhanced GFP (eGFP), enhanced YFP (eYFP) and DsRed have been studied at both the theoretical and experimental levels. In the case of Dronpa, both approaches are consistent in showing the rather counterintuitive result of a larger second-order nonlinear polarizability (or first hyperpolarizability) for the protonated state, which has a higher transition energy, than for the deprotonated, fluorescent state with its absorption at lower energy. Moreover, the hyperpolarizability value for the protonated form of Dronpa is among the highest reported for proteins. In addition to the pH dependence, we have found wavelength dependence in the values. These properties are essential for the practical use of Dronpa or other GFP-like fluorescent proteins as second-order nonlinear fluorophores for symmetry-sensitive nonlinear microscopy imaging and as nonlinear optical sensors for electrophysiological processes. An accurate value of the first hyperpolarizability is also essential for any qualitative analysis of the nonlinear images.

New type of nanomaterials has been synthesized using irridoidic extract derived from Plantago sp. The irridoidic compounds were separated from Plantago lanceolata by successive extraction in aqueous media. The composition of the stable nano-emulsion used for nanomaterials synthesis has been chosen from the pseudo ternary phase diagram and the dimensions of the emulsion were confirmed by Dynamic Light Scattering measurements. The obtained nanodrops were then encapsulated in silica resulting porous core - shell particles which were characterized by Dynamic Light Scattering and electronic microscopy confirming the nanostructure of the new biomaterials.

Nanomaterials obtained from irridoidic extract were used for preclinical tests performed on mice in order to establish the influence of biomaterials on the cicatrisation and diarrhoea. The results obtained revealed a positive action on the cicatrisation process, and the crude extract processed as nanopowder showed a protective action against diarrhoea disorder.