Designing protein nano-construct in ionic liquid: a boost in efficacy of cytochrome C under stresses.

Herein, we present a simple approach to fabricate protein nanoconstructs by complexing cytochrome C (Cyt C) with silk nanofibrils (SNF) and choline dihydrogen phosphate ionic liquid (IL). The peroxidase activity of the IL modified Cyt C nanoconstruct (Cyt C + SNF + IL) increased significantly (2.5 to 10-fold) over unmodified Cyt C and showed enhanced catalytic activity and stability under harsh conditions, proving its potential as a suitable protein packaging strategy.

Sorption based easy-to-use low-cost filters derived from invasive weed biomass for dye contaminated water cleanup.

Today, the development of functional nanostructured materials with specified morphologies utilizing environmentally friendly techniques is a very appealing topic in materials chemistry. Much emphasis has recently been paid to the utilization of biomass to make functional carbonaceous materials of varying forms, specifically carbon helices, with greater implications for the environment, economy, and society. A metal-catalyzed chemical vapour deposition technique has been developed for the fabrication of such carbon helices from nonrenewable hydrocarbons. Also, functionalization approaches were seen to necessitate high temperatures, hazardous gases, and multi-step processes. Herein, we have synthesized tendril-like functional carbon helices (HTCs) from toxic bio-weed, Parthenium hysterophorus as the carbon source by a greener solvothermal method employing deep eutectic solvent (DES) as both soft template and catalyst. Further, for the first time by taking advantage of the in-built chemical functionalities, HTCs were physically activated in an inert atmosphere at 900 °C (AHC) and functionalized with manganese oxide at room temperature by employing DES. Furthermore, the materials were characterized using FE-SEM, EDX, FT-IR, XRD, and BET analysis, where a surface area of 313.12 m2 g-1 was achieved with a robust removal of 99.68% of methylene blue (MB) dye with a flux rate of 7432.71 LMH in a simulated continuous flow system. The obtained material was also evaluated for its specificity towards contaminant removal from an aqueous medium. Thus, Mn3O4/AHC membranes exhibited great promise as an easy-to-use filter for organic contaminant cleanup, with about 91% rejection of MB even at the end of the 10th cycle, indicating its potential.

Multifunctional solvothermal carbon derived from alginate using 'water-in-deep eutectic solvents' for enhancing enzyme activity.

Herein, the use of a "water-in-deep eutectic solvent (DES)" system has been shown as an alternative platform for the low temperature conversion of alginic acid (AA) to a multifunctional aliginate derived carbon (AAC) material with variable oxygen functionalities. Using the in-built oxygenated functionalities in AAC, cytochrome-c (Cyt-c) was immobilised on the surface of AACs and the peroxidase activity of the enzyme was studied. Remarkably, the enzymatic activity was enhanced up to 5.5-fold compared to the native protein without compromising the structural stability of Cyt-c. Altogether, the present study demonstrates a sustainable process for the preparation of AACs and shows their beneficial effect on the activity and stability of Cyt-c, and thus, their application as a protein-friendly material for biotechnological applications.

Biomolecule-derived quantum dots for sustainable optoelectronics.

The diverse chemical functionalities and wide availability of biomolecules make them essential and cost-effective resources for the fabrication of zero-dimensional quantum dots (QDs, also known as bio-dots) with extraordinary properties, such as high photoluminescence quantum yield, tunable emission, photo and chemical stability, excellent aqueous solubility, scalability, and biocompatibility. The additional advantages of scalability, tunable optical features and presence of heteroatoms make them suitable alternatives to conventional metal-based semiconductor QDs in the field of bioimaging, biosensing, drug delivery, solar cells, photocatalysis, and light-emitting devices. Furthermore, a recent focus of the scientific community has been on QD-based sustainable optoelectronics due to the primary concern of partially mitigating the current energy demand without affecting the environment. Hence, it is noteworthy to focus on the sustainable optoelectronic applications of biomolecule-derived QDs, which have tunable optical features, biocompatibility and the scope of scalability. This review addresses the recent advances in the synthesis, properties, and optoelectronic applications of biomolecule-derived QDs (especially, carbon- and graphene-based QDs (C-QDs and G-QDs, respectively)) and discloses their merits and disadvantages, challenges and future prospects in the field of sustainable optoelectronics. In brief, the current review focuses on two major issues: (i) the advantages of two families of carbon nanomaterials (i.e. C-QDs and G-QDs) derived from biomolecules of various categories, for instance (a) plant extracts including fruits, flowers, leaves, seeds, peels, and vegetables; (b) simple sugars and polysaccharides; (c) different amino acids and proteins; (d) nucleic acids, bacteria and fungi; and (e) biomasses and their waste and (ii) their applications as light-emitting diodes (LEDs), display systems, solar cells, photocatalysts and photo detectors. This review will not only bring a new paradigm towards the construction of advanced, sustainable and environment-friendly optoelectronic devices using natural resources and waste, but also provides critical insights to inspire researchers ranging from material chemists and chemical engineers to biotechnologists to search for exciting developments of this field and consequently make an advance step towards future bio-optoelectronics.

Low intensity sonosynthesis of iron carbide@iron oxide core-shell nanoparticles.

Here we demonstrate a simple method for the organic sonosynthesis of stable Iron Carbide@Iron Oxide core-shell nanoparticles (ICIONPs) stabilized by oleic acid surface modification. This robust synthesis route is based on the sonochemistry reaction of organometallic precursor like Fe(CO)5 in octanol using low intensity ultrasonic bath. As obtained, nanoparticles diameter sizes were measured around 6.38 nm ±â€¯1.34 with a hydrodynamic diameter around 25 nm and an estimated polydispersity of 0.27. Core-Shell structure of nanoparticles was confirmed using HR-TEM and XPS characterization tools in which a core made up of iron carbide (Fe3C) and a shell of magnetite (γ-Fe2O3) was found. The overall nanoparticle presented ferromagnetic behavior at 4 K by SQUID. With these characteristics, the ICIONPs can be potentially used in various applications such as theranostic agent due to their properties obtained from the iron oxides and iron carbide phases.

Development of high-performance supercapacitor electrode derived from sugar industry spent wash waste.

This study aims at developing supercapacitor materials from sugar and distillery industry wastes, thereby mediating waste disposal problem through reuse. In a two-step process, biomethanated spent wash (BMSW) was acid treated to produce solid waste sludge and waste water with significantly reduced total organic carbon (TOC) and biological oxygen demand (BOD) content. Further, waste sludge was directly calcined in presence of activating agent ZnCl2 in inert atmosphere resulting in high surface area (730-900m2g-1) carbon of unique hexagonal morphology. Present technique resulted in achieving two-faceted target of liquid-solid waste remediation and production of high-performance carbon material. The resulted high surface area carbon was tested in both three and two electrode systems. Electrochemical tests viz. cyclic voltammetry, galvanostatic charge-discharge and impedance measurement were carried out in aqueous KOH electrolyte yielding specific capacitance as high as 120Fg-1, whereas all solid supercapacitor devised using PVA/H3PO4 polyelectrolyte showed stable capacitance of 105Fg-1 at 0.2Ag-1. The presence of transition metal particles and hetero-atoms on carbon surface were confirmed by XPS, EDX and TEM analysis which enhanced the conductivity and imparted pseudocapacitance to some extent into the working electrode. The present study successfully demonstrated production of high-performance electrode material from dirtiest wastewater making process green, sustainable and economically viable.

Collective osmotic shock in ordered materials.

Osmotic shock in a vesicle or cell is the stress build-up and subsequent rupture of the phospholipid membrane that occurs when a relatively high concentration of salt is unable to cross the membrane and instead an inflow of water alleviates the salt concentration gradient. This is a well-known failure mechanism for cells and vesicles (for example, hypotonic shock) and metal alloys (for example, hydrogen embrittlement). We propose the concept of collective osmotic shock, whereby a coordinated explosive fracture resulting from multiplexing the singular effects of osmotic shock at discrete sites within an ordered material results in regular bicontinuous structures. The concept is demonstrated here using self-assembled block copolymer micelles, yet it is applicable to organized heterogeneous materials where a minority component can be selectively degraded and solvated whilst ensconced in a matrix capable of plastic deformation. We discuss the application of these self-supported, perforated multilayer materials in photonics, nanofiltration and optoelectronics.

Synthesis, characterization, and photocatalytic activity of TiO2/SiO2 nanoparticles loaded on carbon nanofiber web.

TiO2/SiO2 catalysts were loaded on carbon nanofibers (CNF) support by sol-gel preparation and followed by a dip-coating and heat treatment up to 900 degrees C in inert atmosphere. The photocatalytic activities of the catalysts (TiO2/SiO2)/CNF were tested by the photocatalytic degradation rate of methylene blue (MB) under UV irradiation. It was found that (TiO2/SiO2)/CNF showed a higher photocatalytic activity than TiO2/CNF only. It was analyzed that SiO2 contributed to an increase the photo catalytic activity by suppressing the phase transformation of the TiO2 crystals from anatase to rutile on the heat treatment up to 900 degrees C.

In-situ deposition of iron oxide nanoparticles on polyacrylonitrile-based nanofibers by chemico-thermal reduction method.

Polyacrylonitrile (PAN)-based nanocomposite fibers were prepared by co-precipitation of different amounts of Fe(II) and Fe(III) in an alkaline medium to get iron oxide impregnated nanofibers. Nanofibers web were prepared from blend solution of PAN containing different concentrations (1, 2 and 3 wt%) of ferrous (Fe2+)/ferric (Fe3+) solution in the 1:2 molar ratio in an effort to further improvement of the porosity and thereby, electrical properties. Electrospun fibers containing various concentrations of iron salts were then treated with KOH solution to produce nanosized magnetite particles in situ within the PAN nanofibers by precipitating Fe2+ ions or mixture of Fe2+ and Fe3+ ions. Such nanoscale particles homogeneously dispersed in PAN nanofibers to form the three-dimensional network structure. The homogeneously dispersed nanoparticles of iron oxide in and on the PAN carbon nanofibers produced the network structure of reasonably well-aligned configuration. Composite nanofibers morphologies and surface properties were discussed utilizing the combined techniques viz., field emission scanning electron microscope (FE-SEM), particle size analyzer, surface area and pore size distribution measurements.