Table of contents

There is increased interest in organic nanotechnology and biomolecular electronics for environmental preservation, and in their anticipated impact on the economics of both the developing and the developed world. Keeping this in mind, the Department of Biological Functions, Graduate School of Life Sciences and Systems Engineering, Kyushu Institute of Technology (KIT), Kitakyushu, Japan, and the Department of Science & Technology Centre on Biomolecular Electronics (DSTCBE), National Physical Laboratory (NPL) jointly organized the India-Japan Workshop on Biomolecular Electronics and Organic Nanotechnology for Environmental Preservation (IJWBME 2009) at NPL, New Delhi from 17^th - 19^th December 2009, IJWBME 2011 at EGRET Himeji, Himeji, from 7^th - 10^th December, Japan, and IJWBME 2013 at Delhi Technological University, New Delhi, from 13^th - 15^th December. The India-Japan Expert Group Meeting on Biomolecular Electronics & Organic Nanotechnology for Environment Preservation (IJEGMBE) will be held from 22^th – 25^th, December, 2015, at Nakamura Centenary Memorial Hall, Kyushu Institute of Technology, Kitakyushu, Japan in association with Delhi Technological University, Delhi, India.

Recent years have seen rapid growth in the area of Biomolecular Electronics involving the association and expertise of physicists, biologists, chemists, electronics engineers and information technologists. There is increasing interest in the development of nanotechnology and biomolecular electronic devices for the preservation of our precious environment. In this context, the world of the electronics, which developed on Si semiconductors, is going to change drastically. A paradigm shift towards organic or printed electronics is more likely in the future. The field of organic electronics promises exciting new technologies based on inexpensive and mechanically flexible electronic devices, and is now starting to see commercial success. On the sidelines of this increasingly well-established field are several emerging technologies with innovative mechanisms and functions that utilize the mixed ionic/electronic conducting character of conjugated organic materials. These techniques are based around flexible or printed electronics. Ionic functionalization influences many of the key properties of conductive polymers through its impacts on molecular order, the injection and transport of charge, optical excitations, and interactions with other molecules. Consequently, it is an important tool in the development of electronic and photonic devices based on conductive polymers. We have considered that to focus exclusively on the iontronics, ionic carriers in organic electronic materials and devices in organic electronic materials seems timely. Therefore, this report reviews the scientific understanding and important scientific discoveries made in the electrochemistry of conductive polymers based on our experience.

The main purpose of IJEGMBE is to provide an opportunity for researchers, who are interested in biomolecular electronics and organic nanotechnology for environmental preservation, to come together in an informal and friendly atmosphere and exchange their technical information and experience. We are sure that this meeting will be very useful and fruitful for all participants to summarize the recent progress in biomolecular electronics and organic nanotechnology for environmental preservation and prepare the next step for future generations.

Many papers have been submitted from India and Japan and more than 20 papers have been accepted for presentation. All the papers accepted will be presented. The main topics of interest are as follows;

Bioelectronics

Biomolecular Electronics

Fabrication Techniques

Self-assembled monolayers

Nano sensors

Environmental monitoring

Organic devices

Organic Functional Materials

Others

The program of this meeting consists of Invited Lectures and oral presentations. We hope all participants benefited from this meeting. We would like to express our sincere thanks to the organizing committee members of this workshop and thank organizations such as by Japan Society for the Promotion of Science (JSPS), Japan, Department of Science & Technology (DST), Govt. of India, Delhi Technological University (DTU), India, Kitakyushu City, and West Japan Industry and Trade Convention Association for their financial support. Thanks are also given to University of Hyogo and the Kyushu Institute of Technology. Many people have made efforts so as to make this meeting possible and valuable, and we would like to express our thanks to Prof. Wataru Takashima, Prof. Shuichi Nagamatsu, Prof. Shyam S. Pandey, and Ms. Megumi Furuta of Kyushu Institute of Technology, Prof. Ashutosh Sharma (DST, India), Dr Navin Vasishta (DST, India), Prof. Yogesh Singh (DTU, India), Prof. Akihiko Fujii and Dr. Hirotake Kajii from Osaka University for their efforts in planning and arranging this expert group meeting.

Finally, we hope that many young and active researchers who are participating will enjoy stimulating discussions and exchanging their ideas with each other at the IJEGMBE being organized at Kitakyushu in Japan.

All papers published in this volume of Journal of Physics: Conference Series have been peer reviewed through processes administered by the proceedings Editors. Reviews were conducted by expert referees to the professional and scientific standards expected of a proceedings journal published by IOP Publishing.

Novel n-type conducting polymer, poly (p-methylpyridinium vinylene), PMePyV were synthesized by using the quaternization of poly (p-pyridyl vinylene), PPyV and several regiochemical consequences in this polymer were proposed. The electrical, optical, and electrochemical properties of n-type conductive polymer were observed. In addition, a possibility of a variety of functional applications of n-type conductive polymer was indicated.

A far-red sensitive unsymmetrical squaraine dye SQ-41 has been synthesized and subjected to the fabrication of dye-sensitized solar cells by varying the various parameters in order attain optimum photoconversion efficiency (η). It has been demonstrated that an optimum ratio of dye to coadsorber, thickness of mesoporous TiO₂ layer, redox electrolyte and surface treatment are necessary to enhance overall external η. In the case of surface treatment, it has been shown to exhibit pronounced device performance when both of the FTO as well mesoporous TiO₂ surfaces were treated with aqueous TiCl₄. In spite of very high molar extinction coefficient of dye SQ-41, 10-12 µm thickness of mesoporous TiO₂ was found to be necessary to attain the maximum η.

Mechanically stacked and series connected tandem dye sensitized solar cells (T-DSSCs) are fabricated in novel architectures. The architecture consist of TCO tandem DSSCs stacked with TCO-less back contact DSSCs as bottom electrodes (TCO-less tandem DSSCs). Resulting TCO-less tandem DSSCs architecture finds its usefulness in efficient photon harvesting due to improved light transmission and enhanced photons reaching to the bottom electrodes. The fabricated tandem performance was verified with visible light harvesting model dyes D131 and N719 as a proof of concept and provided the photoconversion efficiency (PCE) of 6.06% under simulated condition. Introduction of panchromatic photon harvesting by utilizing near infrared light absorbing Si-phthalocyanine dye in combination with the modified tandem DSSC architecture led to enhancement in the PCE up to 7.19%.

Artificial muscles (or soft actuators) based on electroactive polymers (EAPs) are attractive power sources to drive human-like robots in place of electrical motor, because they are quiet, powerful, light weight and compact. Among EAPs for soft actuators, conducting polymers are superior in strain, stress, deformation form and driving voltage compared with the other EAPs. In this paper, the research trends of EAPs and conducting polymers are reviewed by retrieval of the papers and patents. The research activity of EAP actuators showed the maximum around 2010 and somehow declining now days. The reasons for the reducing activity are found to be partly due to problems of conducting polymer actuators for the practical application. The unique characteristics of conducting polymer actuators are mentioned in terms of the basic mechanisms of actuation, creeping, training effect and shape retention under high tensile loads. The issues and limitation of conducting polymer soft actuators are discussed.

Orientation characteristics of non-regiocontrolled poly (3-hexylthiophene) (NR-P3HT) films prepared by dynamic casting of floating film and transferring method (FTM) has been investigated. The film was first cast on liquid-substrate to obtain as a floating-film followed by its transfer on solid-substrate such as white-glass or Si-wafer in order to evaluate their optoelectronic characteristics. As a possible key-factor to generate the orientation of conjugated polymer in this method we focused on the components of liquid-substrate in this study. The orientation dependence upon various liquid-substrates reveals that dichroic ratio strongly changes with liquid-substrates. Pictures of floating-film show the change in size of floating-parts depending upon the liquid-substrate, representing the expansion length of casting solution upon the viscosity. These findings have indicated that spreading speed of polymer solution and solvent evaporation speed controls the size of floating-film leading to change in the orientation intensity. The multilayer coatings of oriented NR-P3HT films were used for polarized FTIR analysis exhibiting clear dichroism. The obtained dichroic characteristics were well corresponded with in-plane, out-of-plane and non-oriented vibronic modes of P3HT.

Charge carrier mobility in blend films of two types of soluble phthalocyanine derivatives with different substituent length, 1, 4, 8, 11, 15, 18, 22, 25-octapentyl-phthalocyanine (C5PcH₂) and 1, 4, 8, 11, 15, 18, 22, 25-octahexyl-phthalocyanine (C6PcH₂) has been investigated. The charge carrier mobility was measured by the time-of-flight technique. In the case of C5PcH₂ blend ratio below 25 mol%, the high mobility, such as 0.8-1.1 cm²V^-1s^-1 for hole and 0.6 cm²V^-1s^-1 for electron, were obtained at room temperature. In the thin films with C5PcH₂ above 30 mol%, the charge carrier mobility decreased by one order of magnitude and had the different temperature dependence from that below 25 mol%. The marked change of the charge carrier mobility depending on the blend ratio of phthalocyanine derivatives has been discussed by taking the miscibility and the molecular packing structure into consideration.

This work reports on a sensitive and selective genosensor fabrication method for Escherichia coli (E.coli) detection. The functionalized multiwalled carbon nanotubes (MWCNT) synthesized via chemical vapour deposition have been deposited electrophoretically onto indium tin oxide coated glass surface and have been utilized as matrices for the covalent immobilization of E.coli specific probe oligonucleotide that was identified from the 16s rRNA coding region of the E.coli genome. This fabricated functionalized MWCNT based platform sought to provide improved fundamental characteristics to electrode interface in terms of electro-active surface area and diffusion coefficient. Electrochemical cyclic voltammetry revealed that this genosensor exhibits a linear response to complementary DNA in the concentration range of 10^-7 to 10^-12 M with a detection limit of 1×10^-12 M.

Various spectroscopic data for doped conjugated polymers are reviewed and discussed. Chemical doping induces polaron states in the conjugated polymers. Two polaron states appear between the π and π^* states. Third harmonic generation spectroscopy reveals the multiply-resonant nonlinear optical processes using the polaron states. The terahertz measurements clarify the carrier localization, which is dependent on the doping levels. The ultrafast luminescence measurements reveal the relaxation process of the photoexcited states of the doped conjugated polymers.

Fluorinated polymer nanoparticle films were prepared by dissolving amphiphilic fluorinated polymer, poly (N-1H, 1H-pentadecafluorooctylmethacrylamide) (pC7F15MAA) in two miscible solvents (AK-225 and acetic acid). A superhydrophobic and porous film was obtained by dropcasting the solution on substrates. With higher ratios of AK-225 to acetic acid, pC7F15MAA was densified around acetic acid droplets, leading to the formation of pC7F15MAA nanoparticles. The condition of the nanoparticle film preparation was investigated by varying the mixing ratio or total concentration. A highly sensitive dissolved oxygen sensor system was successfully prepared utilizing a smart surface of superhydrophobic and porous pC7F15MAA nanoparticle film. The sensitivity showed I₀/I₄₀ = 126 in the range of dissolved oxygen concentration of 0 ~ 40 mg L^-1. The oxygen sensitivity was compared with that of previous reports.

We report results of studies relating to the fabrication of a paper based impedimetric biosensor using poly (3,4ethylenedioxythiophene):poly (4-styrene sulfonate) (PEDOT:PSS) modified Whatman paper. The layer-by-layer assembly of PEDOT:PSS deposited on the paper substrate results in the formation of a stable, conductive and homogenous film. The film has been characterized using Fourier transfer Infrared spectroscopy and scanning electron microscopy. This conducting paper platform has been used for the conjugation of anti-carcinoembryonic antigen (CEA) protein for quantitative estimation of CEA, a cancer biomarker that is frequently used in detection and monitoring of cancer. The results of the electrochemical impedimetric response studies indicate that the fabricated paper electrode can be used to estimate CEA in the range from 6-20 ngmL^-1, has sensitivity of 3.6 Ω mL ng^-1 with a lower detection limit of 2.68 ng mL^-1.

Biosensors have enormous potential to contribute to the evolution of new molecular diagnostic techniques for patients suffering with cancerous diseases. A major obstacle preventing faster development of biosensors pertains to the fact that cancer is a highly complex set of diseases. The oncologists currently rely on a few biomarkers and histological characterization of tumors. Some of the signatures include epigenetic and genetic markers, protein profiles, changes in gene expression, and post-translational modifications of proteins. These molecular signatures offer new opportunities for development of biosensors for cancer detection. In this context, conducting paper has recently been found to play an important role towards the fabrication of a biosensor for cancer biomarker detection. In this paper we will focus on results of some of the recent studies obtained in our laboratories relating to fabrication and application of nanomaterial modified paper based biosensors for cancer biomarker detection.

A model far-red sensitive symmetrical squaraine dye (SQ-3) and unsymmetrical near infra-red sensitive cyanine dye (UCD-1) bearing direct–COOH functionalized indole ring were synthesized, characterized and subjected to photophysical investigations including their interaction with bovine serum albumin (BSA) as a model protein in phosphate buffer solution (PBS). Both of the dyes exhibit strong interaction with BSA in phosphate buffer with high apparent binding constant. A judicious tuning of hydrophobic main backbone with reactive functionality for associative interaction with active site of BSA has been found to be necessary for BSA detection in PBS.

Vertically aligned ZnO nanorods were grown on a SiO₂/Si surface by optimization of the temperature and atmosphere for annealing of the seed. The seed layer annealed at 500 °C in vacuum provided well separated and uniform seeds which also provided the best condition to get densely packed, uniformly distributed, and vertically aligned nanorods. These nanorods grown on the substrates were used to fabricate electrolyte-insulator-semiconductor (EIS) devices for pH sensing. Etching of ZnO at acidic pH prevents the direct use of nanorods for pH sensing. Therefore, the nanorods functionalised with 3-aminopropyltriethoxysilane (APTES) were utilized for pH sensing and showed the pH sensitivity of 50.1 mV/pH. APTES is also known to be used as a linker to immobilize biomolecules (such as antibodies). The EIS device with APTES functionalized nanorods was used for the label free detection of prostate-specific antigen (PSA). Finally, voltage shifts of 23 mV and 35 mV were observed with PSA concentrations of 1 ng/ml and 100 ng/ml, respectively.

Graphene oxide (GO), due to its excellent electrochemical properties and large surface area, known to be highly suitable material for biosensing application. Here, we report in situ synthesis of silver nanopaticles (AgNPs) onto the GO sheets for the electrochemical detection of Salmonella typhimurium (S.typhimurium). The GO-AgNPs composites have been deposited onto the indium tin oxide (ITO) coated glass substrate by the electrophoretic deposition technique. Carbodiimide coupling (EDC-NHS) has been used for the immobilization of antibodies of Salmonella typhimurium (anti-S.typhimurium) for detection of S.typhimurium. The electron microscopy and UV-visible studies reveal successful synthesis GO-AgNPs composites while FT-IR studies suggest the proper immobilization of anti-S.typhi. The cyclic voltammetry (CV) has been utilized for detection using anti-S.typhi/GOAgNPs/ITO based immunoelectrode as a function of S.typhimurium concentration. The fabricated immunosensor shows improved sensitivity of 33.04 μACFU_-1mLcm_-2 in a wide detection range of 10₁ to 10₆ CFUmL_-1. This immunosensor may be utilized for the detection of other food borne pathogens like aflatoxin and E.coli also.

Methylation frequently occurs in cytosines of CpG sites to regulate gene expression. The identification of aberrant methylation of certain genes is important for cancer marker analysis. The aim of this study was to determine the methylation frequency in DNA samples of unknown length and/or concentration. Unmethylated cytosine is known to be converted to thymine following bisulfite treatment and subsequent PCR. For this reason, the AT content in DNA increases with an increasing number of methylation sites. In this study, the fluorescein-carrying bis-acridinyl peptide (FKA) molecule was used for the detection of methylation frequency. FKA contains fluorescein and two acridine moieties, which together allow for the determination of the AT content of double-stranded DNA fragments. Methylated and unmethylated human genomes were subjected to bisulfide treatment and subsequent PCR using primers specific for the CFTR, CDH4, DBC1, and NPY genes. The AT content in the resulting PCR products was estimated by FKA, and AT content estimations were found to be in good agreement with those determined by DNA sequencing. This newly developed method may be useful for determining methylation frequencies of many PCR products by measuring the fluorescence in samples excited at two different wavelengths.

Polymer light emitting diodes (PLEDs) with a device configuration of ITO/PEDOT:PSS/PFONPN01 [Poly [2,7-(9,9'-dioctylfluorene)-co-N-phenyl-1,8-naphthalimide (99:01)]/LiF/Al have been fabricated by varying the emissive layer (EML) thickness (40/65/80/130 nm) and the influence of EML thickness on the electrical characteristics of PLED has been studied. PLED can be modelled as a simple combination of resistors and capacitors. The impedance spectroscopy analysis showed that the devices with different EML thickness had different values of parallel resistance (R_P) and the parallel capacitance (C_P). The impedance of the devices is found to increase with increasing EML thickness resulting in an increase in the driving voltage. The device with an emissive layer thickness of 80nm, spin coated from a solution of concentration 15 mg/mL is found to give the best device performance with a maximum brightness value of 5226 cd/m².

The performance of organic field-effect transistors (OFETs) fabricated utilizing vacuum deposited n-type conjugated molecule N,N'-Dioctadecyl-1,4,5,8-naphthalenetetracarboxylic diimide (NDIOD2) were investigated using single and bilayer dielectric system over a low-cost glass substrate. Single layer device structure consists of Poly (vinyl alcohol) (PVA) as the dielectric material whereas the bilayer systems contain two different device configuration namely aluminum oxide/Poly (vinyl alcohol) (Al₂O₃/PVA) and aluminum oxide/Poly (methyl mefhacrylate) (Al₂O₃/PMMA) in order to reduce the operating voltage and improve the device performance. It was observed that the devices with Al₂O₃/PMMA bilayer dielectric system and top contact aluminum electrodes exhibit excellent n-channel behaviour under vacuum compared to the other two structures with electron mobility value of 0.32 cm²/Vs, threshold voltages ~1.8 V and current on/off ratio ~10⁴, operating under a very low voltage (6 V). These devices demonstrate highly stable electrical behaviour under multiple scans and low threshold voltage instability in vacuum condition even after 7 days than the Al₂O₃/PVA device structure. This low operating voltage, high performance OTFT device with bilayer dielectric system is expected to have diverse applications in the next generation of OTFT technologies.

In the organic light-emitting diode, the multilayer structure is useful to achieve the effective carrier injection and transport, and improve the emission efficiency. The characteristics of the polymer light-emitting device with a functional layer by contact printing method are investigated. Hole transport material, the guest and electron transport material are mixed at each layer with the same host. Poly (9,9-dioctylfluorene) (F8) and Tris[1-phenylisoquinolinato-C2,N]iridium(III) (Ir(piq)₃) are used as the host and guest materials. We focused on the effects of a functional layer with 1,3,5-Tris (1-phenyl-1H-benzimidazol-2-yl)benzene(TPBi) as the electron transport material doped in F8. For a non-heterostructure device with F8:TPBi functional layer, electrons are injected from the cathode interface to TPBi and transported through F8. TPBi acts as the effective hole blocking and electron transport layer as TPBi is mixed in F8 at the cathode side. Non-heterostructure device exhibits improved emission efficiency and lower driving voltage.

A growth promotion effect of steelmaking slag on Spirulina platensis M135 was investigated. The growth promotion effect was obtained that was 1.27 times greater than that obtained by the control by adding 500 mg L⁻¹ of steelmaking slag and culturing for 60 days. The lipid content decreased in a concentration-dependent manner with steelmaking slag, whereas the carbohydrate content remained constant. The protein content of S. platensis M135 increased in a concentration-dependent manner with steelmaking slag when cultured at day 45. The superoxide dismutase activity of S. platensis M135 exhibited a decreasing trend in a time-dependent manner and an increasing trend in the control. The superoxide dismutase activity was lower than that of the control at day 1 but was higher at day 30. No genetic damage was observed up to 500 mg L⁻¹ of steelmaking slag at 30 days of culture. Recovery from genetic damage was observed at 1,000 mg L⁻¹ of steelmaking slag but not at higher concentrations.

In this paper cascaded H-bridge multilevel inverter (CHBMLI) has been investigated for the application of renewable energy generation. Energy sources like solar, wind, hydro, biomass or combination of these can be manipulated to obtain alternative sources for renewable energy generation. These renewable energy sources have different electrical characteristics like DC or AC level so it is challenging to use generated power by connecting to grid or load directly. The renewable energy source require specific power electronics converter as an interface for conditioning generated power .The multilevel inverter can be utilized for renewable energy sources in two different modes, the power generation mode (stand-alone mode), and compensator mode (statcom). The performance of the multilevel inverter has been compared with two level inverter. In power generation mode CHBMLI supplies the active and reactive power required by the different loads. For operation in compensator mode the indirect current control based on synchronous reference frame theory (SRFT) ensures the grid operating in unity power factor and compensate harmonics and reactive power.

Microwave and millimeter-wave devices including a liquid crystal (LC) are increasingly attractive for the use in adaptive and controllable devices. Various types of microwave phase shifters having an LC transmission line have been studied (e.g. microstripline, coplanar waveguide, and rectangular waveguide). In conventional microwave devices, the response time after removal of voltage is slow because the LC layer in the devices is usually thick. In this study, the time response of the LC permittivity is studied experimentally and theoretically. Experimentally measured response curves having two time constants for decay are examined by using Frank's continuum theory with and without the backflow effect.

Discotic liquid crystals are emerging as novel nanomaterials useful in many device applications. Recently their hybridization with various zero-, one- and two- dimensional metallic and semiconducting nanoparticles has been realized to alter and improve their thermal, supramolecular and electronic properties. In this article, we have overviewed the work carried out in our laboratories on the dispersion of various metallic, semiconducting and carbon nanoparticles in discotic liquid crystals. First a brief introduction of self-organizing supramolecular liquid crystalline materials is presented with an emphasis on discotic liquid crystals. This is followed by the description of various discotic liquid crystal-nanoparticle hybrid systems. A number of discotic liquid crystals, functionalized nanoparticles and their nanocomposites were prepared and studied by spectroscopic and analytical tools. The dispersion of such functionalized nanomaterials in columnar matrix enhances the physical properties such as, conductivity, photoconductivity, absorbance, etc., significantly without disturbing the supramolecular properties.