In order to address the pressing demand for newer broad-spectrum antifungal medicines with enhanced activity, computer modelling was utilised to rationally develop newer antifungal azole-based drugs.

Design and development of novel eco-friendly materials with outstanding antimicrobial properties have transpired to impede and regulate the growth of pathogenic microorganisms. Bionanocomposites are the propitious aspirant to circumvent the global warming emanates and proliferation in pollution attributed to biocompatibility, degradability, and environmental benign primacy. Undoubtedly, silver nanoparticles are the magic bullet that has efficient antimicrobial properties against various bacterial strains. The synchronous existence of chitosan and Ag nanoparticles are the two crucial protruding antibacterial agents that divulged imperious antibacterial properties against gram-positive strains in comparison to gram-negative strains. This indagation will shed light on the experimentation and analysis of chitosan/PVA biohybrid grafted with graphene and silver nanoparticles for screening of antibacterial efficiency. The tensile strength of 15% GO/CS/Ag/PVA was found to be 81.99 MPa as compared to pristine chitosan which was 36 MPa. The active resultant bio-nano hybrid fabricated via a biomimetic approach evinced magnificently thermostable, mechanically robust, and antibacterial properties which make it a potential candidate for packaging applications. The results revealed that the inhibition is relatively dependent upon concentration. It has been noticed that a better antibacterial effect was shown by gram-positive bacteria contrary to gram-negative strains for GO-reinforced CS films owing to the presence of silver nanoparticles.

Polysaccharides are an idiosyncratic source of organic natural materials apropos structural diversity, functionalities, and abundance. In their indigenous state, few of their functionalities inhabit their material form as hydrogels, consequently proffering molecular tactics to be exploited. Recently, polysaccharide-based hydrogels utilizing the Schiff base bonds or dynamic imine chemistry as crosslinks have been widely explored owing to their high sensitivity, good flexibility, enhanced recyclability, stimuli-responsiveness, and tissue adhesion. The polysaccharide-derived Schiff base hydrogels bestow elementary fabrication, self-healing properties, and injectibility under physiological conditions, resulting in mechanical forces that result in the augmentation of gel precursors. These hierarchical constructs can be tuned for mechanically, morphologically, and biochemically different microenvironments, thus finding numerous applications in a variety of fields. Herein, we comprehensively analyze the constitutive nature, state-of-the-art design principles, gelling mechanism, and structural or mechanical properties of dynamic polysaccharide-Schiff-based hydrogels. In a dynamic covalent bond polysaccharide framework, various interactions such as hydrogen bonding, hydrophobic interactions, and metal–ligand interactions produce toughness, high strength, and environmental responsiveness. We propound that polysaccharide hydrogels based on dynamic Schiff base linkages proffer advantages owing to the dynamic interfacial imine formation that can translate changes in bonding to macroscopic outputs. Emerging strategies that may enhance and ameliorate the properties, current scope and functionalities along with current challenges to the field have been assessed to impart guidelines for the rational design of these dynamic hydrogel systems.

An aspartame-based AB-type diketopiperazine monomer, cyclo(l-aspartyl-4-amino-l-phenylalanyl) (ADKP), was synthesized and subsequently utilized in the polycondensation of homo-polyamides with high molecular weights. By using various amino acids, dicarboxylic acids, and diamines, random DKP-based copolymers were also synthesized. The self-assembly properties of ADKP and poly(cyclo(l-aspartyl-4-amino-l-phenylalanyl)) (PA1) were studied via the solvent displacement method. Notably, PA1 self-assembled into particles with various morphologies in different solvent systems, such as irregular networks, ellipsoids, and hollow particles. The morphological transformation was also confirmed by dropping acetone and toluene onto the PA1 particles. Furthermore, infrared spectra and Hansen solubility parameters of PA1 and different solvents revealed the particle formation mechanism, which provided more insights into the relationship between the morphology and strength of the hydrogen bonding of each solvent.

Cinnamate-based polyesters were synthesized, including poly(4-hydroxycinnamic acid), poly(4-hydroxy-3-methoxycinnamic acid), poly(3-hydroxycinnamic acid) (P3HCA), and hyperbranched poly(3,4-dihydroxycinnamic acid) (PdHCA). These materials were further processed into hard and dry membranes by casting and underwent photoreactions by ultraviolet (UV) light. The photodeformation behavior of the linear and hyperbranched polyester containing membranes with cinnamate derivatives in the main chain was observed macroscopically and microscopically. The PdHCA and P3HCA membranes were amorphous and exhibited photodeformations. The PdHCA surface visibly contracts, which is a typically observed phenomenon in photoresponsive polymers; however, the P3HCA surface showed a unique photoexpansion behavior. Time-resolution infrared spectroscopy of the P3HCA film revealed trans-to-cis isomerism in the polymer main chains that bent convexly as a result of photoexpansion of the UV-irradiated regions. Furthermore, photomasking created a micropattern on the P3HCA film, which supported the photoexpansion mechanism of the P3HCA film.

Self-assembling polyimides (PIs) having diketopiperazine (DKP) components were synthesized by polycondensation of a 4-amino-l-phenylalanine (4APhe) dimer, an aromatic diamine newly designed in this study. The amino acid-derived PIs showed high thermal resistance, with a 10% weight loss temperature (T d10) of 432 °C at the maximum, and did not show any glass transition below the thermal decomposition temperature. The poly(amic acid) (PAA) precursors formed nanospheres upon reprecipitation over dimethylacetamide into water. The nanospheres were then added to solvents with different polarities and sonicated to induce deformation of the spherical forms into spiky balls, flakes, or rods. The PAA particle morphologies were retained in the PIs after the two-step imidization. Finally, the PI particles with self-assembling DKP moieties were formed, and their morphologies were fine-tuned using different mixed solvents.

In recent years, carbon-based nanomaterials have evolved as the most widely discussed, researched, and applied synthetic nanomaterials, due to their impressive characteristics. Carbon materials present innumerable benefits over other conventionally used materials. Carbon-based nanomaterials, including CNTs, graphene, graphene oxide (GO), fullerene, and nanodiamonds, have been extensively explored and evaluated for their applications in environmental monitoring, food safety control, healthcare, etc., owing to their remarkable characteristics, in particular their high mechanical stability, high surface area, versatility, and functionality. This review article discusses recent advancements in carbon nanostructured material-based sensors, addressing synthesis, characterization, structure-property relationships, and applications, covering recently published works.

The current review focuses on the comprehensive studies of platinum-based complexes that are known to exhibit anticancer properties. The research on metal-particle work has helped in treating sicknesses which plays an imperative part in therapeutic bioinorganic science. Understanding the biochemistry of the detoxification mechanism of metals can help in advancing as well as enhancing the anticancer property of metal complexes for several types of a tumour. The classifications of complexes discussed have been done on the basis of Platinum oxidation states and binding sites of the ligands. Further background and current status of Pt(IV) complexes are briefly explained along with a special reference to Structural Activity Relationships and Mode of Action. The coordination chemistry of Pt(IV) has been summarised and Pt(IV) complexes are reviewed on the basis of binding of Pt(IV) with Human Serum Albumin and DNA. Finally, the results were summarized and concluded emphasizing on the most important features.

4-Aminophenylalanine (4APhe), an exotic amino acid which is obtained as a microorganism metabolite of glucose, is polycondensed with various tetracarboxylic dianhydrides as a diamine monomer to obtain poly(amic acid)s. Subsequent thermal imidization of poly(amic acid)s is made at 220 °C with stepwise heating from 100 °C. Some of the obtained polyimides (PIs) exhibited good solubility in organic solvents such as N,N-dimethylformamide, N,N-dimethylacetamide, and more. The progress of imidization was observed by proton nuclear magnetic resonance and infrared spectroscopy to confirm that the imidization ratio was up to 98%. Carboxylate group of the side-chains of PIs affected their solubilities despite the high imidization ratio, and the solubility was lost for any organic solvents by decarboxylation at 280 °C, confirmed from mass-loss of thermogravimetric analysis. Thus, a new series of PIs were obtained with abilities of solvent-molding in PI state and thermal resistivity enhancement by further heating after molding.

Nanotechnology is a useful tool in providing solutions to issues related to water treatment, especially the technical challenges related to the removal of contaminants such as pathogens, toxic heavy metals, pesticides, and other persistent and toxic chemicals. It is a ground-breaking technology having the potential to overcome challenges faced in the current water treatment crisis. There is an immediate requirement for efficient and innovative water treatment technologies to ensure safe drinking water, elimination of micropollutants, and intensification of industrial production processes through utilization of flexible water treatment systems. Nanomaterials are efficient, low-cost, and eco-friendly alternatives to existing treatment materials because they process superior efficiency and distinctive characteristics, such as a high reaction rate and surface-to-mass ratio. This chapter extensively covers the use of green methods of water treatment since ancient times to the present. Some of the metals in their nanoforms are more efficient and are used more than others. The role of some of the specific nanometals and their roles as catalysts and membranes has been elaborated upon and presented in detail.

Novel titanium and vanadium based trimetallic oxide nanocomposites (TMONCs) have been synthesized using metal salts of titanium-vanadium along with three others metals viz. tin, aluminium and zinc as precursors by the sol-gel method. Aqueous ammonia and hydrazine hydrate were used as the reducing agents. The preparations of nanocomposites were monitored by observing the visual changes during each step of synthesis. The synthesized TMONCs were characterized using UV-vis, SEM, EDX, TEM and DLS. Band gap of the synthesized TMONCs ranges from 3-4.5 eV determined using tauc plot. FTIR study revealed the molecular stretching and bending peaks of corresponding M-O/M-O-M bonds thus confirming their formation. Molecular composition and particle size were determined using EDX and DLS respectively. Molecular shape, size and surface morphology have been examined by SEM and TEM.

Human activities in past decades have raised serious issues related to the environment and its conservation. Air pollution, poor management of waste, growing water scarcity, falling groundwater tables, water pollution, preservation and quality of forests, biodiversity loss, and land/soil degradation, global climate change, pollution, environmental degradation, resource depletion, and genetically modified foods are the current environmental problems that make us vulnerable to disasters and tragedies, now and in the future. For environmental issues including pollution of air and water, pollution related to heavy metals, and contamination of food, nanomaterials may be used as a promising and effective tool to overcome major challenges in the development of remediation methods that help in the protection of the environment. In this chapter, the essential aspects of environmental problems will be reviewed and then the application of new nanomaterials, which can serve as environmental cleaners, will be discussed.

Cancer treatment using platinum has vastly been associated with numerous side effects and resistance generation. As a result, current medicinal chemistry is now emphasized on the development of novel metal based drugs bearing diverse pharmacological profile. There has been an increasing interest in the drafting of Au(III) complexes as new metal based drugs. Au(III) complexes have been observed to be especially steady under different physicochemical situations. Dithiocarbamato-Au(III) complexes show antiproliferative property against specific human tumor cells because of their inhibiting effect towards the tumor cell augmentation. The review focuses on the results obtained in the field of anticancer and antimicrobial efficacy of Au(III) complexes. The represented Au(III) complexes as anticancer agents have been classified as (a) complexes containing Au-N bonds, (b) complexes containing Au-S bonds and (c) complexes containing Au-O bonds. Au(III) complexes as antimicrobial agents have been subdivided as (a) antibacterial and antifungal (b) antimalarial and (c) antitrypanosomial Au(III) complexes. The results obtained from the analysis of anticancer and antimicrobial Au(III) complexes could possibly lead to the design and development of novel potent Au(III) complexes exhibiting enhanced activities.

Nanosized titania has promising application in the field of photocatalysis, optical coating and solar cell. Metal alkoxides based sol–gel methodology is one of the established & extensively used route for the preparation of nano-titania. In present work, nanosized titania have been prepared through sol–gel transformation of synthesised and chemically modified metal complex using titanium(IV) isopropoxide (TTIP). Modifications of metal alkoxides with chelating ligands result in the controlled condensation of TTIP. Metal complexes of TTIP were chemically modified by various schiffs bases. Phase of nano-sized titania was confirmed by X-ray diffraction and Fourier transform infrared spectroscopy. Shape, size and surface morphology were examined using scanning electron microscopy and high-resolution transmission electron micsroscopy. Elemental composition was investigated by energy disperse X-ray analysis. The absorption spectra and thus optical band gap were determined using Ultraviolet and visible spectroscopy.

Structural investigation of polymers by various available analytical methods is important in order to correlate the structure with polymer properties for which understanding of polymer structure is very important factor. The data presented here in this article shows the 1H NMR spectra used for the characterization of prepared poly(amic acid)s (PAAs). It is often difficult to assigns the peak in NMR of polymers due to its complexity. Data presented here helps in assigning the proton peak in complex NMR of PAAs prepared from aromatic diamines. Further functionality in polymer chains can be confirmed by FT-IR spectra. Change in functionality during some reaction or process can be monitored by disappearance or appearance of peaks in FT-IR. The complete imidization of PAAs to Polyimides (PIs) is difficult to analyze because of the chemical stability i.e. insolubility of PIs in most of the solvent therefore the completion of imidization process was confirmed using FTIR.

For the first time, any type of plant extract from the medicinally important plant Combretum indicum has been used for the biosynthesis of silver nanoparticles (AgNPs). The present investigation reports the synthesis and characterization of AgNPs using the flower petal extract of Combretum indicum. For monitoring the formation and optical properties of the synthesized nanoparticles, they were analyzed using UV-visible spectroscopy. Apart from this, the luminescence properties were also studied by photoluminescence (PL) spectroscopy. Scanning electron microscopy (SEM) analysis revealed the formation of AgNPs and the surface morphology has been determined. The mean particle diameter using the dynamic light scattering (DLS) technique ranged from 50–120 nm depending upon the reaction time. The atomic percentage of Ag in synthesized NPs and the crystallinity were determined by energy dispersive x-ray (EDX) and x-ray diffraction (XRD), respectively. This green approach of synthesizing AgNPs, using a biologically important plant extract is found to be cost effective, economical, eco-friendly and convenient in synthesis.

AbstractA nanocomposite of 0.5SnO2–0.5Al2O3 has been synthesized using a sol-gel route. Structural and optical properties of the nanocomposite have been discussed in detail. Powder X-ray diffraction and scanning electron microscopy with energy-dispersive X-ray diffraction spectroscopy confirm the phase purity and the particle size of the 0.5SnO2–0.5Al2O3 nanocomposite (13 to 15 nm). The scanning electron microscopy also confirms the porosity in the sample, useful in sensing applications. The FT-IR analysis confirms the presence of physical interaction between SnO2 and Al2O3 due to the slight shifting and broadening of characteristic bands. The UV-Vis analysis confirms the semiconducting nature because of direct transition of electrons into the 0.5SnO2–0.5Al2O3 nanocomposites.

We have developed a novel route for the synthesis of high-performance bio-polyimides (PIs) microbially-derived from photo-responsive aromatic diamine 4,4'-diaminostilbene (DAS) and its reduced counterpart 4, 4'-(ethane-1,2-diyl) dianiline (EDDA). DAS and EDDA were condensed with various commercially-available dianhydrides to obtain a series of poly(amic acid)s (PAAs) and PIs which were characterized in terms of their thermal, mechanical, and photo-functions. These bio-based PAAs showed a very high viscosity of 6.62 dL/g, and the PIs showed ultrahigh thermal resistance with T-d10 values over 600 degrees C, which were higher than that of any bio-based plastic reported thus far. They also showed T-g values above 250 degrees C, and tensile strength of over 132 MPa, which is higher than that of Kapton (TM). The PIs also showed photo-functional behavior based on stilbene-based photoreactions. (C) 2015 Elsevier Ltd. All rights reserved.