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Syed Arshad Hussain

Publications and source records attributed to Syed Arshad Hussain.

At least 19 recordsLinked to original sources

Bio-Organic Materials Based Resistive Switching Memories

Resistive switching (RS) devices, based on soft materials such as organic, biomolecules as well as natural plant extracts etc., has emerged as a promising alternative to the conventional memory technologies. They offer simple device structures, low power requirements, rapid switching and compatibility with high-density device integration. Over the last two decades, these classes of materials have been explored for both non-volatile memory and artificial synapse functions. This chapter provides a brief overview of RS fundamentals, their major classifications, key applications, and recent trends in the use of organic and bio-derived materials.

cond-mat.mtrl-sci↗

An account of Natural material based Non Volatile Memory Device

The development in electronic sector has brought a remarkable change in the life style of mankind. At the same time this technological advancement results adverse effect on environment due to the use of toxic and non degradable materials in various electronic devices. With the emergence of environmental problems, the green, reprogrammable, biodegradable, sustainable and environmental-friendly electronic devices have become one of the best solutions for protecting our environment from hazardous materials without compromising the growth of the electronic industry. Natural material has emerged as the promising candidate for the next generation electronic devices due to its easy processing, transparency, flexibility, abundant resources, sustainability, recyclability, and simple extraction. This review targets the characteristics, advancements, role, limitations, and prospects of using natural materials as the functional layer of a resistive switching memory device with a primary focus on the switching/memory properties. Among the available memory devices, resistive random access memory (RRAM), write once read many (WORM) unipolar memory etc. devices have a huge potential to become the non-volatile memory of the next generation owing to their simple structure, high scalability, and low power consumption. The motivation behind this work is to promote the use of natural materials in electronic devices and attract researchers towards a green solution of hazardous problems associated with the electronic devices.

cond-mat.mtrl-sci↗

Resistive switching of tetraindolyl derivative in ultrathin films: A potential candidate for non-volatile memory applications

Bipolar resistive switching using organic molecule is very promising for memory application owing to their advantages like simple device structure, low manufacturing cost, their stability and flexibility etc. Herein we report Langmuir-Blodgett and spin-coated film based bipolar resistive switching devices using organic material indole derivative. Pressure - area per molecule isotherm, Brewster Angle Microscopy, Atomic Force Microscopy and Scanning Electron Microscopy were used to have an idea about organization and morphology of the organic material onto thin film. Based on device structure and measurement protocol it is observed that the device made up of 1 shows non-volatile Resistive Random Access Memory behaviour with very high memory window, data sustainability and repeatability.Oxidation-reduction process as well as electric field driven conduction are the key behind such switching behaviour.Due to very good data retention, repeatability, stability and high device yield the switching device designed using compound 1may be a potential candidate for memory applications.

cond-mat.mtrl-sci↗

Fluorescence Resonance Energy Transfer (FRET) as Biomarkers

Applications of Fluorescence Resonance Energy Transfer (FRET) in biology have expanded tremendously in the last 25 years. This technique has become a staple technique in many biological and biophysical fields. FRET based chemical sensors and biosensors can play an important role as biomarkers. Development of new and effective FRET based assay for biological application is an emerging area of research needing multidisciplinary approach from biologists, chemists and physicists. Here we have discussed the use of FRET technique as biomarker.

physics.bio-ph↗

Resistive Switching Behaviour of Organic Molecules

Organic electronics is very promising due to the flexibility, modifiability as well as variety of the available organic molecules. Efforts are going on to use organic materials for the realization of memory devices. In this regard resistive switching devices surely will play a key role. In this paper an effort has been made to illustrate the general information about resistive switching devices as well as switching mechanisms involving organic materials. As a whole a general overview of the emerging topic resistive switching has been given.

physics.app-ph↗

Effect of Functional Group on Electrical Switching Behaviour of an Imidazole Derivative in Langmuir-Blodgett Film

Here we report the design and synthesis of an imidazole derivative namely 1-benzyl-2,4,5-triaryl imidazole and its switching behaviour assembled onto Langmuir-Blodgett films. Monolayer characteristic of imidazole at the air-water interface has been studied by surface pressure vs area per molecule isotherm, hysteresis analysis and insitu Brewster Angle Microscopy . These studies indicated the formation of stable floating Langmuir film at the water subphase. Atomic Force Microscopy investigation confirmed the successful deposition of the Langmuir film onto solid substrate. Device consisted of 60 layers LB films of imidazole showed resistive bipolar switching behaviour irrespective of the first applied bias voltage polarity. Observed bipolar switching has been explained in terms of reduction oxidation process. Due to the presence of strong reducible group C double bond N in the imidazole core, reduction oxidation process takes place easily during bias. Presence of sharp reduction and oxidation peaks in the Cyclic Voltammetry measurement of 2 also supported this hypothesis. Presence of benzyl group with the imidazole core played the crucial rule in the reduction oxidation process and hence the switching behaviour. When benzyl group was replaced by a H then bipolar switching was not observed. In that case oxidizable group NH opposed the reduction process during bias. This type of bipolar switching is very promising for future technological applications in organic electronics.

physics.app-ph↗

Fluorescence and FRET based mercury (II) sensor

A mercury (II) sensor has been proposed based on Fluorescence Resonance Energy Transfer (FRET) between N,N'-dioctadecyl thiacyanine perchlorate (NK) and Octadecyl rhodamine B chloride (RhB). Out of these two molecules NK is sensitive to Hg2+ ions due to presence of sulfur atom in it. Accordingly, presence of Hg2+ ions affects the NK fluorescence as well as FRET from NK to RhB. Our results showed that NK fluorescence intensity and FRET efficiency linearly decreases with increase in Hg2+ ion concentration. With proper optimization present system under investigations can be used to sense Hg2+ ions in aqueous solution with detection limit of 9.13 ppb. Advantage of this present system is that it is very simple compared to the other FRET based system and also it works under aqueous environment. This method has also been tested using real lake water and satisfactory results were obtained.

cond-mat.mtrl-sci↗

Monolayer characteristics of chitosan assembled in Langmuir films mixed with arachidic acid

Here we report the monolayer characteristics of a biodegradable polymer chitosan using Langmuir-Blodgett film technique. Usually chitosan has not form stable monolayer film. However they form stable monolayer film when mixed with fatty acid. Our result may be useful for the biological application of chitosan mainly in drug delivery. Since, the stability during the time of drug delivery is one of the important criteria for the choice of biomaterials suitable for forming the carrier film matrix and the barrier films.

cond-mat.mtrl-sci↗

Formation of fluorescent H aggregates of a cyanine dye in LB films and its effect on energy transfer

Here we report the formation of fluorescent H aggregates of a cyanine dye Oxa18 in ultrathin film and its effect on energy transfer between Oxa18 and sRhb. Ideally H aggregate do not fluoresce. However, due to imperfect stacking of Oxa18 molecules in the aggregates, fluorescence occurred from Oxa18 H aggregates. This H aggregated band has substantial effect on the enhancement of energy transfer from Oxa18 to sRhb both in solution and in ultrathin film.

cond-mat.mtrl-sci↗

Sensing of DNA conformation based on change in FRET efficiency between laser dyes

This communication reports the effect of DNA conformation on fluorescence resonance energy transfer (FRET) efficiency between two laser dyes in layer by layer (LbL) self assembled film. The dyes Acraflavine and Rhodamine B were attached onto the negative phosphate backbones of DNA in LbL film through electrostatic attraction. Then FRET between these dyes was investigated. Increase in pH or temperature causes the denaturation of DNA followed by coil formation of single stranded DNA. As a result the FRET efficiency also changed along with it. These observations demonstrated that by observing the change in FRET efficiency between two laser dyes in presence of DNA it is possible to detect the altered DNA conformation in the changed environment.

cond-mat.mtrl-sci↗

Effect of nanoclay laponite and pH on the energy transfer between fluorescent dyes

Fluorescence resonance energy transfer (FRET) between two dyes acriflavine (Acf) and rhodamine B (RhB) were investigated in solution and Layer-by-Layer (LbL) self assembled films in presence and absence of clay mineral laponite. UV-Vis absorption and fluorescence spectroscopy studies suggest both the dyes present mainly as monomer in solution and films. Energy transfer occurred from Acf to RhB in solution and LbL films. The energy transfer efficiency increases in presence of clay laponite and the maximum efficiency were 78.17% and 32.54% in clay dispersion and in LbL films respectively. Presence of laponite particles onto LbL film was confirmed by atomic force microscopy investigations with a surface coverage of more than 75%. Energy transfer efficiency was pH sensitive and the energy transfer efficiency varies from 4.5% to 44.45% in mixed dye solution for a change in pH from 3.0 to 12.0. With proper calibration it is possible to use the present system under investigation to sense pH over a wide range of pH from 3.0 to 12.0.

cond-mat.mtrl-sci↗

Development of hard water sensor using Fluorescence Resonance Energy Transfer

A method is presented for the sensing of water hardness by determining the concentration of calcium and magnesium in water, based on Fluorescence resonance energy transfer (FRET) process. The principle of the proposed sensor is based on the change of FRET efficiency between two laser dyes Acriflavine (Acf) and Rhodamine B (RhB) in presence of permanent hard water components (CaCl2 and MgCl2). Nanodimensional clay platelet laponite was used to enhance the efficiency of the sensor.

cond-mat.mtrl-sci↗

Fluorescence Resonance Energy Transfer (FRET) sensor

The applications of Fluorescence resonance energy transfer (FRET) have expanded tremendously in the last 25 years, and the technique has become a staple technique in many biological and biophysical fields. FRET can be used as spectroscopic ruler in various areas such as structural elucidation of biological molecules and their interactions, in vitro assays, in vivo monitoring in cellular research, nucleic acid analysis, signal transduction, light harvesting, and metallic nanomaterials etc. Based on the mechanism of FRET a variety of novel chemical sensors and Biosensors have been developed. This review highlights the recent applications of sensitive and selective ratiometric FRET based sensors.

physics.bio-ph↗

Development of a DNA sensor using molecular logic gate

This communication reports the increase in fluorescence resonance energy transfer (FRET) efficiency between two laser dyes in presence of Deoxyribonucleic acid (DNA). Two types of molecular logic gates have been designed where DNA acts as input signal and fluorescence intensity of different bands are taken as output signal. Use of these logic gates as DNA sensor has been demonstrated

physics.bio-ph↗

Development of an Ion-Sensor using Fluorescence Resonance Energy Transfer

A method is presented for the sensing of ions by determining the concentration of corresponding salts (KCl, NaCl, MgCl2, CaCl2, FeCl3, FeSO4, AlCl3) in water, based on Fluorescence resonance energy transfer (FRET) process. The principle of the proposed sensor is based on the change of FRET efficiency between two laser dyes Acriflavine and Rhodamine B in presence of different ions (K+, Na+, Mg2+, Ca2+, Fe2+, Fe3+, Al3+). Nanodimensional clay platelet laponite was used to enhance the efficiency of the sensor.

cond-mat.mtrl-sci↗

Nano dimensional hybrid organo-clay Langmuir-Blodgett films

Clay mineral particles are interesting nanosized building blocks due to their high aspect ratio and the chemical properties. The main interest in this nanosized building blocks results essentially from the colloidal size and the permanent structural charge of the particles. Smectites or swelling clay minerals are naturally occurring nanomaterials that can be fully delaminated to elementary clay mineral platelets in dilute aqueous dispersion. This dilute aqueous smectite suspensions are well suited to convert into functional nanofilms. The functionalization is performed by ion exchange reaction with amphiphilic molecules carrying the desired functionality, such as chirality, two photon absorption, energy transfer, optical nonlinearity and magnetism, which are due to the nature of the amphiphilic cations and to the organization of both the amphiphilic molecules and the elementary clay mineral platelets. Controlling the structure of materials at the nanometre scale is of fundamental importance for tailoring such materials properties. Langmuir Blodgett films are known for a high degree of organisation of organic molecules. Fundamental research into the organization of molecules at clay mineral platelets is necessary to optimize the materials for specific applications. This paper gives an overview of organo-clay hybrid Langmuir-Blodgett nano films.

cond-mat.mtrl-sci↗

J-aggregates of thiacyanine dye organized in LB films: effect of irradiation of light

In the present communication we report the preparation and characterizations of Langmuir and Langmuir-Blodgett films of a thiacyanine dye-dioctadecyl thiacyanine perchlorate (NK) mixed with Octadecyl trimethyl ammonium bromide (OTAB). The relationship between the molar ratio of OTAB and NK and the orientation of molecules at the air-water interface was investigated using surface pressure - area per molecule (π-A) isotherm. UV-Vis absorption and fluorescence spectroscopic investigations reveal that prominent J-aggregation of NK molecule was observed in the LB films lifted at higher surface pressure. This J-aggregation can be controlled by diluting the NK molecules with OTAB. It was observed that the J-aggregates of NK decayed to monomer and H-aggregates when the NK-LB film was exposed to a monochromatic light of wavelength 460 nm (Lambda max of J - aggregates).

cond-mat.mtrl-sci↗