المؤلفون: Sukhdev Roy, Mohit Prasad

المصدر: IEEE Transactions on NanoBioscience. 11:410-420

مصطلحات موضوعية: Materials science, Light, Logic, Biomedical Engineering, Pharmaceutical Science, Medicine (miscellaneous), Bioengineering, Laser pumping, Electrical and Electronic Engineering, Thin film, Photocurrent, biology, business.industry, Lasers, Bacteriorhodopsin, Models, Theoretical, Nanosecond, Chromophore, Photochemical Processes, NAND logic, Computer Science Applications, Bacteriorhodopsins, Polyvinyl Alcohol, Excited state, biology.protein, Optoelectronics, business, Biotechnology

الوصف: We present designs of optoelectronic OR, AND, NOR, and NAND logic gates with multiple pulsed pump laser beams based on the photovoltaic response of bacteriorhodopsin (BR) molecules embedded in a polyvinyl matrix coated on ITO. A detailed experimental study of the photovoltaic response reveals that continuous pulsed exposure to 532 nm and 405 nm laser light results in a large photocurrent/photovoltage, due to rapid reprotonation and chromophore reisomerization, taking BR to the ground state in hundreds of nanoseconds. It also helps in sustaining the photovoltage at higher frequencies and in maintaining the shape of the photovoltage. It is shown experimentally that for a pulsed laser beam at 532 nm with peak pump intensity of 1.19 W/cm (2), a photovoltage of 50 mV is generated. A detailed numerical simulation of the photovoltaic response of BR has been carried out taking into account all the six states (B, K, L, M, N, and O) in the BR photocycle to ascertain the effect of various parameters such as lifetime of the M-state, the pump pulse-width, pump intensity, lifetime of excited protons, and rate constant of excited protons. Experimental results are in good agreement with theoretical simulations. The present study opens up new prospects for protein-based optoelectronic computing.

الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::8d16bbd8ab4acf98ae06683e4b32c874Test
https://doi.org/10.1109/tnb.2012.2213840Test

المؤلفون: Paolo Bertoncello, Valter Bavastrello, Cristina Paternolli, Claudio Nicolini, D. Nicolini

المصدر: IEEE Transactions on Nanobioscience. 2:124-132

مصطلحات موضوعية: Materials science, Light, Photochemistry, Biomedical Engineering, Pharmaceutical Science, Medicine (miscellaneous), Bioengineering, Context (language use), Radiation Dosage, law.invention, Electric Power Supplies, Biomimetic Materials, law, Solar cell, Monolayer, Electrochemistry, Solar Energy, Electrical and Electronic Engineering, business.industry, Photovoltaic system, Dose-Response Relationship, Radiation, Membranes, Artificial, Solar energy, Acceptor, Computer Science Applications, Energy Transfer, Chemical engineering, Polymerization, Bacteriorhodopsins, Optoelectronics, Polyvinyls, Cyclic voltammetry, business, Biotechnology

الوصف: The photovoltaic (PV) solar cell, converting incident solar radiation directly into electrical energy, today represents the most common power source for the Earth-orbiting spacecraft, and the utilization of organic materials in this context is here explored in comparison with the present state of the art placing emphasis in organic nanotechnology. Poly[3-3'(vinylcarbazole)] (PVK) was synthesized by oxidative polymerization with ferric chloride of N-vinylcarbazole. The resulting polymer was then deposited on solid support by using the Langmuir-Schaefer (LS) technique. The pressure-area isotherm of PVK revealed the possibility of compact monolayer formation at the air-water interface. Different layers of PVK were doped with iodine vapors. The cyclic voltammetry investigation of PVK-doped I/sub 2/ showed a distinctive electrochemical behavior. The photoinduced charge transfer across a donor/acceptor (D/A) hybrid interface provided an effective method to study the PV properties of the composite LS films. The results are compared with other approaches within the biological framework, such as bacteriorhodopsin (BR), and organic nanostructured materials.

الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::29c67ff2e69994e4b36daf11580f5681Test
https://doi.org/10.1109/tnb.2003.813940Test

المؤلفون: Martin Neebe, Thorsten Fischer, Norbert Hampp, Thorsten Juchem

المصدر: IEEE Transactions on Nanobioscience. 2:1-5

مصطلحات موضوعية: Optics and Photonics, 3D optical data storage, Materials science, Photochemistry, Biomedical Engineering, Information Storage and Retrieval, Pharmaceutical Science, Medicine (miscellaneous), Bioengineering, Optical storage, Encryption, Computers, Molecular, Photochromism, Nanotechnology, Electrical and Electronic Engineering, Computer Security, Electronic Data Processing, business.industry, Lasers, Reading (computer), Optical polarization, Computer Science Applications, Identification (information), Bacteriorhodopsins, Optical recording, Optoelectronics, business, Biotechnology

الوصف: The use of bacteriorhodopsin (BR) as an active layer in write-once-read-many optical storage is presented. This novel feature of BR materials may be used on a wide variety of substrates, among them transparent substrates but also paper and plastics. The physical basis of the recording process is polarization-sensitive two-photon absorption. As an example for this new BR application, an identification card equipped with an optical recording strip is presented, which has a capacity of about 1 MB of data. The recording density currently used is 125 kB/cm/sup 2/, which is far from the optical limits but allows operation with cheap terminals using plastic optics. In the examples given, data are stored in blocks of 10 kB each. A special optical encryption procedure allows the stored data to be protected from unauthorized reading. The molecular basis of this property is again the polarization-sensitive recording mechanism. The unique combination of optical storage, photochromism, and traceability of the BR material is combined on the single-molecule level. BR introduces a new quality of storage capability for applications with increased security and anticounterfeiting requirements.

الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::dd304ed13bed2c382111c7ac97770f87Test
https://doi.org/10.1109/tnb.2003.810163Test

المؤلفون: Thorsten Fischer, Norbert Hampp

المصدر: IEEE Transactions on Nanobioscience. 3:118-120

مصطلحات موضوعية: Manufactured Materials, Materials science, Rotation, Polymers, Biomedical Engineering, Pharmaceutical Science, Medicine (miscellaneous), Bioengineering, Coated Materials, Biocompatible, Purple Membrane, Materials Testing, Electrochemistry, Electrical and Electronic Engineering, Composite material, Spinning, chemistry.chemical_classification, Nanotubes, Textiles, Biomolecule, Polymer, Electrospinning, Computer Science Applications, Membrane, chemistry, Bacteriorhodopsins, Nanofiber, Polymer solution, Nanometre, Biotechnology

الوصف: The formation of beaded nanofibers containing purple membrane (PM) by electrospinning of polymer solutions is reported. Electrospinning is known as a versatile method to produce polymeric fibers with diameters on the nanometer scale. Embedding of particles significantly larger than the fiber diameter is unexpected because a breakdown of the spinning process is expected when microscaled particles in the polymer solution pass the nozzle. Presumably due to the flexibility of PM patches, the embedding of the membrane patches into the fibers becomes possible. Embedding into nanofibers may be an alternative to microencapsulation for biomolecules.

الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::1a34044502ef458514b6a209b1b143f6Test
https://doi.org/10.1109/tnb.2004.828220Test

المؤلفون: Norbert Hampp, D. Zeisel

المصدر: IEEE Engineering in Medicine and Biology Magazine. 13:67-74

مصطلحات موضوعية: Optical image, Materials science, biology, business.industry, Biomedical Engineering, Holography, Image processing, Bacteriorhodopsin, General Medicine, Holographic interferometry, law.invention, Optics, law, Electronic speckle pattern interferometry, biology.protein, Bacteriorhodopsins, Time domain, business

الوصف: Mutated bacteriorhodopsins are considered as versatile media in optical image processing. The following topics are discussed: the biological function of bacteriorhodopsin (BR); the photocycle of BR; light-controlled absorption of BR films; BR films in transmission- and reflection-type dynamic holograms; holographic interferometry (image processing in the time domain); holographic pattern recognition (image processing in the space domain). >

الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_________::6334499ca4815fcdef9242d704b6a9b1Test
https://doi.org/10.1109/51.265776Test