The role of self-assembled monolayers in electronic devices Singh, Mandeep; Kaur, Navpreet; Comini, Elisabetta
Journal of materials chemistry. C, Materials for optical and electronic devices,
01/2020, Volume:
8, Issue:
12
Journal Article
Peer reviewed
Open access
Today, the self-assembled monolayer (SAM) approach for surface functionalization is regarded as highly versatile and compelling, especially in the immobilization of biomolecules and fabrication of ...novel supramolecular architectures. Most of the scientific articles recently published on biosensors use the concept of SAM to generate different surface functional groups for the immobilization of biomolecules such as antibodies, proteins, and enzymes. Due to the simplicity of the formation process and lack of requirement for costly instruments, this approach is prominent among researchers working in the field of surface functionalization and biosensing devices. Herein, we have reviewed a wide range of literature reports on electronic devices such as chemical sensors, biosensors and organic film transistors that use SAM concept for their purposes. In this review article, effort has been made to provide information about the SAM functionalization procedure,
i.e.
the technique used, the molarity of the SAM solution, and other physical/chemical conditions involved. Moreover, the fundamental concept of the monolayer, the types of monolayers on air/water interfaces, the techniques used for SAM formation on solid substrates and the use of SAMs for patterning are discussed.
Today, the self-assembled monolayer (SAM) approach for surface functionalization is regarded as highly versatile and compelling, especially in the immobilization of biomolecules and fabrication of novel supramolecular architectures.
•Low cost bioprocess strategies for pullulan production by agro-industrial wastes.•Pullulan production by solid-state and submerged fermentation has been discussed.•Applications of pullulan in ...various food industries have been elaborated.
Pullulan is a microbial exopolysaccharide produced from Aureobasidium pullulans by submerged fermentation of a medium supplemented with carbon, nitrogen and other essential nutrients. These nutrients are expensive which increase the cost of pullulan production. The requirement of alternative cost-effective substrates for pullulan production is a prerequisite. Agro-based industries generate a large volume of solid/liquid waste and its accumulation generates a severe environmental impact. These wastes are composed of carbohydrates, proteins and other constituents, and can be used as substrates for the development of low-cost processes for the production of various microbial products. This could be a good environmental friendly waste management system. Pullulan production from agro-industrial wastes can be carried out by both submerged and solid-state fermentation by A. pullulans. Owing to its unique properties, pullulan has wide applications in many food-based industries. This review highlights pullulan production from agro-industrial wastes and potential applications of pullulan in various food industries.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
•Pullulan as a carrier for targeted drug and gene delivery has been described.•Chemical derivatization of pullulan to various forms has been illustrated.•Applications of pullulan derivatives in drug ...and gene delivery have been explained.
Pullulan is a water soluble exo-polysaccharide produced by yeast like fungus Aureobasidium pullulans. Pullulan structure have a unique characteristic i.e. co-existence of α-(1→4) and α-(1→6) linkages. Pullulan nanoparticle consists of both hydrophobic and hydrophilic characteristics which are due to its unique structure. It can be derivatized via various chemical reactions to increase its utility in the field of pharmaceuticals. Although, various drugs have the potential to become powerful therapeutic medicines, but their safe and targeted delivery to a specific site is a major challenge and rapidly growing area of research. Pullulan–drug conjugates can target infected cells/tissues and exhibit high bioactivity with the release of cytotoxic molecules. The pullulan conjugates can be used for targeted drug delivery as well as targeted gene delivery for the treatment of various diseases in liver, lungs, brain, spleen, etc. In this review, the applications of pullulan and its derivatives in drug and gene targeting are described.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
Low‐cost, non‐noble‐metal electrocatalysts are required for direct methanol fuel cells, but their development has been hindered by limited activity, high onset potential, low conductivity, and poor ...durability. A surface electronic structure tuning strategy is presented, which involves doping of a foreign oxophilic post‐transition metal onto transition metal aerogels to achieve a non‐noble‐metal aerogel Ni97Bi3 with unprecedented electrocatalytic activity and durability in methanol oxidation. Trace amounts of Bi are atomically dispersed on the surface of the Ni97Bi3 aerogel, which leads to an optimum shift of the d‐band center of Ni, large compressive strain of Bi, and greatly increased conductivity of the aerogel. The electrocatalyst is endowed with abundant active sites, efficient electron and mass transfer, resistance to CO poisoning, and outstanding performance in methanol oxidation. This work sheds light on the design of high‐performance non‐noble‐metal electrocatalysts.
Bismuth doping reduces charge‐transfer resistance, creates a strained surface, and optimizes the d‐band center of porous NixBiy aerogels. The optimum benefits of the amorphous structure and abundant superficial oxygenated species are realized in a Ni97Bi3 aerogel, which demonstrates unprecedented electrocatalytic performance in methanol oxidation with both high activity and durability.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
The gas-sensing properties and mechanism and the role of the shell thickness of structurally well-defined SnO2/NiO heterostructures are studied. One-dimensional (1D) SnO2/NiO core–shell nanowires ...(CSNWs) were produced by a two-step process; single-crystalline SnO2-core nanowires (NWs) were synthesized by vapor–liquid–solid (VLS) deposition and then decorated with a polycrystalline NiO-shell layer by atomic layer deposition (ALD). The thickness of the NiO-shell layer was precisely controlled between 2 and 8.2 nm. The electrical conductance of the sensors was decreased many orders of magnitude with the NiO coating, suggesting that the conductivity of the sensors is dominated by Schottky barrier junctions across the n(core)–p(shell) interfaces. The gas-sensing response of pristine SnO2 NWs and SnO2/NiO CSNWs sensors with various thicknesses of the NiO-shell layers was investigated toward hydrogen at various temperatures. The response of the SnO2/NiO-X (X is the number of ALD cycles) CSNWs significantly depends on the thickness of the NiO-shell layer. The SnO2/NiO-100 sensor showed the best performance (NiO-shell thickness ca. 4.1 nm), where the radial modulation of the space-charge region is maximized. The sensing response of the SnO2/NiO-100 sensor was 114 for 500 ppm of hydrogen at 500 °C, which was about four times higher than the response of pristine SnO2 NWs. The sensing mechanism is mainly based on the formation of a p–n junction at the p-NiO-shell and the n-SnO2-core interface and the modulation of the hole-accumulation region in the NiO-shell layer. The remarkable performance of the SnO2/NiO CSNWs sensors toward hydrogen is attributed to the high surface to volume ratio of the 1D SnO2 core-NWs, the conformal NiO shell layer, and the optimized shell layer thickness radially modulating the space-charge regions.
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IJS, KILJ, NUK, PNG, UL, UM
In this contemporary era, wetlands and the entire aquatic diversity are suffering from major pollution problem. Not only the aggregation of higher population in metropolitan causes the production of ...plenty of solid, liquid and gaseous wastes, but also the high-technological industries contribute to a mammoth of wastes in the ecosystem. During the process of industrial effluent discharge into the water bodies, the toxic substances available in these wastes can affect the aquatic flora and fauna, resultantly disturbing the entire system and constituting human health hazards indirectly or directly. The objective of this study was to estimate the nutritional value of the liver and intestine of fish which is being discarded as waste during fish processing and pollution status by calculated water quality index (WQI) and comparison of both wetlands during diverse seasons. WQI of Harike Wetland was observed to be 56.68 which indicates that water quality in this wetland is “poor”, while at Nangal Wetland WQI was calculated to be 39.54 and comes under “good” water quality and safe for the entire ecosystem. HPI (heavy metal pollution index) for Harike Wetland was observed 144.9 and for Nangal Wetland was 3.12, indicating heavy load of heavy metal pollution at test sample site. MI (metal index) value was also detected higher at test sample site (4.76) as compared to that at control site (0.22). The mean total n-3 and n-6 polyunsaturated fatty acids (PUFAs) declined in the liver of test fish samples (Harike Wetland) as compared to control fish (Nangal Wetland) samples except in winter season. Similarly, mean total saturated fatty acids (SFAs) were also found to decline significantly (
p
<0.05) in the liver of test fish sample as compared to control fish sample during autumn and winter seasons. Significant (
p
<0.05) decline of mean total n-3 PUFAs (except winter) and total n-6 PUFAs (except rainy) in the intestine of test fish sample was observed during all the seasons when compared to control fish samples. However, total SFAs were found to increase in the intestine of test fish samples as compared to control fish samples during all the studied seasons. In the present investigation, fluctuations recorded in the water quality parameters and major groups of FAs in the tissues were due to the geographical location and pollution load in the fish samples taken from Harike Wetland.
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CEKLJ, EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
The increasing contamination of environmental media is a serious health issue requiring advanced methods to detect actual and emerging pollutants. In particular, high-sensitivity sensors for ...monitoring water pollutants are under deep investigation. Here, we review the synthesis, optical properties and applications of carbon dots for sensing contaminants in water samples. Fluorescence-based sensors have achieved ultrasensitive detection at nanomolar to picomolar concentrations. Carbon dot sensors have unique advantages such as biocompatibility, easy preparation, optical activity and wide applicability.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
•Recent insights of applications of pullulan in tissue engineering have been discussed.•Pullulan as a scaffold for tissue engineering has been described.•Imperative role of pullulan in bone tissue ...engineering has been elaborated.•Pullulan applications for small and full thickness wound healing have been explained.•Vascular endothelial cells regeneration using pullulan composite scaffolds has been enlightened.
Tissue engineering is a recently emerging line of act which assists the regeneration of damaged tissues, unable to self-repair themselves and in turn, enhances the natural healing potential of patients. The repair of injured tissue can be induced with the help of some artificially created polymer scaffolds for successful tissue regeneration. The pullulan composite scaffolds can be used to enhance the proliferation and differentiation of cells for tissue regeneration. The unique pattern of pullulan with α-(1→4) and α-(1→6) linkages along with the presence of nine hydroxyl groups on its surface, endows the polymer with distinctive physical features required for tissue engineering. Pullulan can be used for vascular engineering, bone repair and skin tissue engineering. Pullulan composite scaffolds can also be used for treatment of injured femoral condyle bone, skull bone and full thickness skin wound of murine models, transversal mandibular and tibial osteotomy in goat, etc. This review article highlights the latest developments on applications of pullulan and its derivatives in tissue engineering.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
A
bstract
We have investigated the pseudo-scalar meson structure in the form of transverse momentum-dependent parton distribution functions (TMDs) in the light-front based holographic model and quark ...model. Starting from leading order, we have calculated all the time-reversal even TMDs for pion and kaon up to twist-4 in these models. We have shown the 3-dimensional structure as well as the 2-dimensional structure of these particles along with their average quark transverse momenta. The parton distribution functions (PDFs) of pseudo-scalar pion have been compared with E615 and modified E615 results. The sum rules, TMD transverse dependence, inverse moments and Gaussian transverse dependence ratio in these models have also been studied. Further, the transverse quark densities have also been analyzed in the momentum space plane for these particles. The higher twist kaon properties in light-front framework have been predicted for the first time in this work.
For the last two decades, titanium dioxide (TiO2) has received wide attention in several areas such as in medicine, sensor technology and solar cell industries. TiO2-based gas sensors have attracted ...significant attention in past decades due to their excellent physical/chemical properties, low cost and high abundance on Earth. In recent years, more and more efforts have been invested for the further improvement in sensing properties of TiO2 by implementing new strategies such as growth of TiO2 in different morphologies. Indeed, in the last five to seven years, 1D nanostructures and heterostructures of TiO2 have been synthesized using different growth techniques and integrated in chemical/gas sensing. Thus, in this review article, we briefly summarize the most important contributions by different researchers within the last five to seven years in fabrication of 1D nanostructures of TiO2-based chemical/gas sensors and the different strategies applied for the improvements of their performances. Moreover, the crystal structure of TiO2, different fabrication techniques used for the growth of TiO2-based 1D nanostructures, their chemical sensing mechanism and sensing performances towards reducing and oxidizing gases have been discussed in detail.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
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