Publications

2024

Gate-to-grave assessment of plastic from recycling to manufacturing of TENG: a comparison between India and Singapore

This study assesses the viability of recycled plastic-based triboelectric nanogenerators (TENGs) for sustainable energy harvesting in India and Singapore, concurrently examining plastic waste management. Using material flow analysis and life cycle assessment, the findings revealed that in Singapore, waste-to-energy incineration has a lower environmental impact than landfilling and mechanical recycling, attributed to natural gas usage. In India, recycling offsets impacts from incineration and landfilling, contributing to a lower net environmental impact. Economic performance of a TENG module from PET recyclates showed a 20% carbon footprint reduction when scaling up from lab to industrial “freeze-drying” processes. Key challenges in TENG manufacturing processes are also assessed for future development. This research highlights the potential of recycled plastic-based TENGs in sustainable energy and waste management.

2023

Microbial Biotechnology for Circular Economy in Wastewater Treatment: Potentials, Technologies, and Challenges

Biological wastewater treatment, as the largest application of biotechnology in the world, has developed for more than a century, and novel postulates for addressing the global challenges of water scarcity and the pollution of aquatic environments have been put forward worldwide. While numerous challenges, though interrelated, have been addressed singly, sporadically alleviating one problem while aggravating others. We posit the absence of a conceptual framework to empirically link wastewater treatment microbiome characteristics (microbial processes, community properties, and membership) to each other and broader system levels that they affect. Accordingly, selected pivotal findings to exemplify past and future roles of wastewater microbiology as a momentous subdiscipline of microbial ecology is presented. Initiation, integration, and optimization of circular economy in wastewater systems with perspicuous potentiality for curtailed energy and chemical use, and augmented energy production and resource recovery aim to transform environmental engineering from forestalling pollution to explicable innovation for sustainable systems engineering. We conclude by discussing the main challenges concerning economics and value chain development, environment and health, and society and policy issues.

Biomimetic nanosystems in theranostics

“Smart” biomimetic materials capable of emulating elements, models, and systems of nature, are appealing therapeutic platforms for the development of next-generation medication and healthcare. The evolution of nanotechnology has initiated a revolution in the biomedical and pharmaceutical fields. Notably, biomimetic nanosystems have emerged as distinctive agents affording both therapeutic and diagnostic functions, often referred to by the portmanteau “nanotheranostics” attributable to their preferable properties including active targeting, immune evading, and prolonged circulation time. The chapter mainly highlights and discusses evolving progress in the fabrication and application of biomimetic nanoparticles, with an emphasis on clinical impact and translation. The challenges and limitations associated with the emerging technology are addressed to contribute to further innovations in the field.

Starch-based nanosystems for theranostic applications

The exploitation of starch and starch-derived materials for a broad range of applications including biomedical and pharmaceutical research is attributable to its idiosyncratic functional and physicochemical attributes. Starch-based nanosystems are utilized in controlled drug and bioactive release as a carrier. The mechanical, morphological, swelling, rheological properties, and digestibility of different starch nanosystems including nanofibers, nanoparticles, nanocrystals, etc. are the key factors that have been the focus of an exponentially increasing number of works devoted to developing nanotheranostics. Because of their broad presence in food, biocompatibility, and biodegradability, starch-based nanotheranostics are contemplated as safe materials. The chapter describes the synthesis strategies, and properties, of starch-based nanosystems as theranostics.

2022

Roadmap to sustainable plastic waste management: a focused study on recycling PET for triboelectric nanogenerator production in Singapore and India

This study explores the implications of plastic waste and recycling management on recyclates for manufacturing clean-energy harvesting devices. The focus is on a comparative analysis of using recycled polyethylene terephthalate (PET) for triboelectric nanogenerator (TENG) production, in two densely populated Asian countries of large economies, namely Singapore and India. Of the total 930,000 tonnes of plastic waste generated in Singapore in 2019, only 4% were recycled and the rest were incinerated. In comparison, India yielded 8.6 million tonnes of plastic waste and 70% were recycled. Both countries have strict recycling goals and have instituted different waste and recycling management regulations. The findings show that the waste policies and legislations, responsibilities and heterogeneity in collection systems and infrastructure of the respective country are the pivotal attributes to successful recycling. Challenges to recycle plastic include segregation, adulterants and macromolecular structure degradation which could influence the recyclate properties and pose challenges for manufacturing products. A model was developed to evaluate the economic value and mechanical potential of PET recyclate. The model predicted a 30% loss of material performance and a 65% loss of economic value after the first recycling cycle. The economic value depreciates to zero with decreasing mechanical performance of plastic after multiple recycling cycles. For understanding how TENG technology could be incorporated into the circular economy, a model has estimated about 20 million and 7300 billion pieces of aerogel mats can be manufactured from the PET bottles disposed in Singapore and India, respectively which were sufficient to produce small-scale TENG devices for all peoples in both countries.

Microplastic profusion in food and drinking water: are microplastics becoming a macroproblem?

Microplastics are extremely complex, and as the food chain comes full circle, it is dreaded that these could have a deleterious influence on humans. Although the risk of plastics to humans is not yet established, their occurrence in food and water destined for human consumption has been reported. The prevalence of micro-sized plastics in the ecosystem and living organisms, their trophic transfer along the food web, and the discernment of food species as competent indicators have become research priorities. The scale of the issue is massive, but what are the main culprits and causes, and could there be a solution in sight for this global problem? Despite the massive amount of research in the field, a collation of available data and pertinent hazard evaluation remains difficult. In order to identify the knowledge gaps and exposure pathways, several traits related to food chain assessment are presented with the goal of properly evaluating and managing this emerging risk. We apprehend three possible noxious consequences of small plastic particles, firstly, due to the plastic particles themselves; secondly, due to the extrication of tenacious organic pollutants adsorbed onto the plastics; and thirdly, due to the leaching of components such as monomers and additives from the plastics. The exigency for the standardization of protocols to bring about consistency in data collection and analysis, involving solutions, stakeholder costs, and benefits, are discussed. Harmonized methods will enable meticulous assessment of the impacts and threats that microplastics pose to the biota and increase the comparability between studies. We emphasize the contribution of the “honest broker” in science, providing an overarching analysis to devise the most viable solutions to microplastic pollution for private and public leadership to utilize. 

Dynamic protein and polypeptide hydrogels based on Sciff base co-assembly for biomedicine

Stimuli-responsive biopolymer hydrogels are promising building blocks for biomedical devices, attributable to their excellent hydrophilicity, biocompatibility, and dynamic responsiveness to temperature, light, pH, and water content. Although hydrogels find interesting applications as drug carriers, therapeutic adhesives, scaffolds for tissue engineering, inks for bioprinting, and biosensors, conventional chemically crosslinked hydrogels often lack adaptive and biomimetic properties needed for diverse biomedical applications. Using dynamic and reversible crosslinks such as the Schiff base bond, biomimetic hydrogels featuring structurally dynamic behaviours, such as shape memory, self-healing properties, and dynamic mechanical resilience, can be developed for in vivo therapy. Natural proteins and polypeptides are non-toxic, biodegradable, and biocompatible biopolymers that serve fundamental structural and biochemical functions in the human body. Besides natural polypeptides, easily processible synthetic polypeptides are protein analogues with widely tunable sequences that form secondary structures. Therefore, natural proteins and synthetic polypeptides are excellent candidates for fabricating Schiff base-linked biomedical hydrogels. This review outlines the functional properties, design approaches, and applications of Schiff base-linked protein and polypeptide hydrogels in tissue engineering, regenerative medicine, wound dressing, drug delivery, bioprinting, and biosensors. The review ends with an outlook of future developments for potential applications of Schiff base-linked protein and polypeptide hydrogels in and beyond biomedicine.

Advances in bioremediation of biosurfactants and biomedical wastes

Current demographic trends, the ascent of immedicable diseases, access to inexpensive generic treatments, and the advent of lifestyle drugs have been pivotal causes of the increased production of biomedical wastes throughout the world. The seemingly endless stream of biomedical wastes has become a topic of global concern and implications due to their presence in surface water, groundwater, soil, etc., and cognate repercussions on vertebrates, invertebrates, and ecosystem structures and functions. Microbes can assist in environmental restoration by binding, oxidizing, volatilizing, immobilizing, or otherwise transmuting pollutants. Bioremediation has the potential to reinstate polluted environments inexpensively yet effectively. The present chapter justifies the need for bioremediation and proffers a holistic study on the development of novel methods and technologies to deal with biomedical wastes. Employing biological surface-active agents produced from microbes has gained considerable attention due to their diverse applicability, biodegradability, low toxicity, effectiveness at extreme conditions of pH and temperature, and low-cost substrates. We discuss the latest progress made and the main properties of biosurfactants followed by an overview of their current use in bioremediation. A thorough investigation on efficacy and toxicity is performed to identify potential limitations and the causes of failures.

Natural polymer-based composite wound dressings

Wound repair is a complicated and firmly synchronized physiological process, entailing the activation of various cell types throughout each succeeding step (homeostasis, inflammation, proliferation, and tissue remodeling). Any impairment within the correct sequence of the healing events could prompt incessant injuries, with probable denouement on the patients’ quality of life, and consequential failures on wound care management. Contemporary wound healing treatments like gauzes and bandages primarily are pivoted on passively cushioning the wound and do not proffer properties that escalate the rate of wound healing. Even though these strategies are resilient at safeguarding any infection after application, they are futile at healing a heretofore infected wound or spurring tissue regeneration. The burgeoning of next-generation wound healing treatments aid in enhancing patient care pathways and clinical outcomes. Natural polymers play a significant role in wound care. They deliver a versatile and tunable platform to design the germane extracellular matrix competent to succor tissue regeneration, while contrasting the onset of adverse events. Our goal is to scrutinize the evolution of natural polymers in wound dressing from traditional to modern-day treatment methods. The chief characteristics and properties of a natural polymer, which is widely utilized as biomaterial, are presented. Properties of composite material with peculiar heed on their applications in the skin tissue repair field are discussed. Finally, the unmet needs and developmental perspectives of the new generations of environmentally friendly, naturally derived, smart wound dressings are addressed in light of future research.

2021

Deciphering the pathways for evaluation of nanotoxicity: Stumbling block in nanotechnology

Nanosafety has been a subject of scrupulous indagation attributed to the ambiguity in terms of harmonizing and perceiving the nano risk evaluation. Nanotoxicity is an emanate pigeonhole of nanotechnology. The burgeoning of commercial products grafted with engineered nanomaterials has been escalated exponentially. Inevitably, the profile of nanomaterials and their repercussions on the ecosystem and mankind must be meticulously assessed. The research fraternity has to evolve innovations to prognosticate the unsought nuisance that does not prevail yet in the frame of reference with nanotoxicity due to the proliferation in the utilization of nanomaterials for consumers’ product. Besides, it is imperative to contemplate whether the size is the only characteristic that matters for the detrimental impacts of nanoscale materials. The design and development of safe nanomaterials substantially in drug discovery could be a benchmark. As safety assessment is of utmost importance, therefore it is pre-eminent to lessen animal analysis by the inception of auxiliary or prognostic in silico and in vitro methods which has become a precedence. To perceive the paradigms in nanotoxicity, this robust indagation will provide comprehensive exploration in clearance, kinetics, metabolism, mapping of fate, and physical properties of toxicity of nanomaterials. First, the different characteristics of engineered nanomaterials linked to different toxicological effects is presented. Accordingly, the mechanism by which nanoparticles exhibit toxicity is delineated to aid in nanoparticle redesign to reduce their impact. Second, an overview of the physiochemical techniques and biochemical methodologies adopted for characterization of nanoparticles for testing and screening their toxicological effects is presented. Third, adverse impact of nanoparticle toxicity on human and environment is highlighted. Finally, the challenging pathways and significant strategies to eradicate the risk of nanotoxocity is addressed to proffer a solid rationale in translating the promises of nanotechnology.

The paradigm in conversion of plastic waste into value added materials

The global proliferation of plastic waste is a dire concern as fumble wastes in the environment degrade plastics into smaller fragments that pose a prodigious menace to biota. Plastics are persistent due to their inherent properties which have found omnipresent applications in automotive, electronics, energy, adhesives, household components, paints, coatings, and the myriad of medical fields, etc. Nevertheless, plastics have a caliginous side. However, plausible methods and cogent techniques to deal with emerging plastic wastes have not been established which results in the amalgamation of waste creating havoc. The cognizance of fostering and sharing of actual management of plastic wastes involving harmonization of specific standards and practices could assist inappropriate management of plastic wastes. Moreover, the conversion of plastic waste into a gamut of applications such as energy recovery, components of building construction, production of nanomaterials, evolve novel monomers, etc could be a propitious endeavor for mankind. Nevertheless, the diminution of ubiquitous concern should headway from the end-of-pipe approach to pre-emptive strategies by utilizing the plastic wastes into intrinsic applications or by eradicating the single-use plastics. This exploration will proffer a vision in the conversion of waste into gimmick applications useful for mankind and to contemplate whether recycling is the only magic bullet or we could utilize it head-on.

Invigoration of polymer bioinks for additive manufacturing of human tissues and organs

The emanating paragon of personalized medical care utilizes discrete patient data to customize clinical therapy. While the principal cynosure so far is the formulation of ameliorated therapeutics contingent on “omics” data, the notion outstretches all embodiments of customized treatment. Howbeit, the dearth of in vitro tissue and organ models competent of mimicking human physiology gravely impede the development and clinical translation of drugs and therapies with higher in vivo efficiency. Bioprinting (a form of additive manufacturing) enables us to effectively address the perpetual limitations for the manufacturing of hierarchically organized living constructs with complex structural and functional organization through the precise spatial positioning of multiple materials and cells. Additive manufacturing translates computer-aided design virtual 3D models into physical objects. By digital splicing of tomographic data, 3D scan, or computer-aided design, layer-by-layer fabrication of target objects can be achieved bereft the requirement for molds or machining. As polymeric materials are by far the most exploited class of materials, the anecdote discusses the processing of polymers and the development of polymers and advanced polymeric systems, especially for bioprinting. Facets of polymer design, additives, and processing parameters as they harmonize to exalting build speed and improved veracity, stability, functionality, mechanical attributes, porosity, and surface finish are explored. As the field matures, additive manufacturing is poised to proffer patient-specific tissue and organ substitutes, reproducible microtissues for drug screening and disease modeling, personalized drug delivery systems, as well as customized medical devices; therefore, we also highlight the most pressing challenges facing the research domain to revolutionize modern medicine and healthcare.

Inherent roadmap of conversion of plastic waste into energy and its life cycle assessment: A frontrunner compendium

The gargantuan escalation in the myriad of plastic waste in emerging and developing countries has led to the augmented atrocities concerning the environmental impact and health disquietude due to their ubiquitous nature. Burgeoning in the conversion of plastic waste into energy is a captivating strategy to circumvent the power generation shortages, greenhouse gas emissions, restricted space for landfilling, and can unravel the emanation of plastic waste disposal. Indeed, this transformation sporadically enunciated as a magic bullet to address all impediments created by plastics in municipal solid waste. Plastic waste recycling has empirical significance and commercial worth for recuperation of resources and environmental welfare but to attain sustainable development, emphasis on the metamorphosis of waste into energy by employing greener technologies should be implemented. Howbeit, the prolegomenon of plastic waste to energy innovation is usually jeopardized by recurrent deterrents like operation costs, fund investments, environmental laws, etc. In this contrivance, assessment and fate of plastic waste to energy has been addressed to harmonize the nuisance originated by prevailing plastic wastes. The design and fabrication of technology implemented to transform plastic waste into energy have been inscribed by demarcating challenges and hindrances with their life cycle assessment process. Novel integrated energy plants employing renewable sources such as solar cells for revamping plastic trash are discussed aiming to motivate communities to recycle and reuse the waste in a sustainable way. Circuit based simulation model proffers an estimation of the electrical behaviour of renewable energy integrated systems with respect to alterations in environmental parameters including temperature and irradiation. This robust overview also unfurls the bottlenecks in the valorization of plastic waste into energy with bestowing potential panacea towards a better sustainable society.

Schiff base metallodrugs in antimicrobial and anticancer chemotherapy applications: a comprehensive review

The proliferation in cancer and multidrug-resistant infections amidst personage with the evolution of civilization is an alarming bone of contention. Cancer has long been the pre-eminent core of death worldwide; additionally, it paves the way for a large portion of the microbial infections, hence increasing the implications. Nonetheless, the wide rate of multidrug opposition in both diseases entails the progression of potential molecules with intended characteristics that could dodge multidrug-resistant issues. A fruitful methodology for chemotherapy has been the employment of drugs with metal as active ingredients that can be utilized to treat multi-resistant infections more effectively. Schiff bases have been imperative, inferable from their adaptable metal chelating properties, innate organic exercises, and adaptability to alter the structure to tweak it for specific natural applications. With the advent of the modern pharmaceutical industry, biochemical approaches to forestalling and treating disease have procured a new level of prominence in the evolving relationship between microbes and their human hosts. This review gives an insight into some indispensable biological aspects of Schiff bases in light of their antibacterial and anticancer activity and discusses the potential and eventual fate of this class of metallodrugs either as anticancer or antimicrobial specialists.

Antibacterial efficacy of poly (vinyl alcohol) nanocomposites reinforced with graphene oxide and silver nanoparticles for packaging applications

Antibiotic resistance is a major threat to public health and food security. Attributable to the heightening occurrence and proliferation of antibiotic-resistant pathogenic microorganisms, the development of antimicrobial packaging has emerged as a promising technology. Poly (vinyl alcohol) (PVA), a water-soluble synthetic polymer is contemplated as a promising biocompatible, biodegradable, and low cytotoxic material for various medical, industrial, and commercial applications. To stretch its applications, the polymer material was doped with graphene oxide (GO) decorated with silver nanoparticles (Ag). In this study, an eco-friendly, facile, one-step chemical reduction route was employed for the synthesis of nanocomposites by an Ag nanoparticle anchored on GO nanoparticle. The polymer nanocomposite thin film was prepared by solution casting technique. Homogeneity of dispersion and surface morphology was examined by scanning electron microscope investigation. The inclusion of GO-Ag nanocomposite in the polymer matrix increases the roughness of the film confirmed by atomic force microscopy analysis. The increment in properties was attributable to excellent H bonding between PVA and GO wherein molecules are strongly intercalated with each other. The tensile strength, as well as thermal stability of the PVA/GO/Ag thin films, was significantly enhanced on the incorporation of GO/Ag nanoparticles confirmed by TGA analysis. PVA/GO/Ag nanocomposites exhibited effective antibacterial activity against gram-positive bacteria Staphylococcus aureus and gram-negative bacteria Escherichia coli. In contrast, no inhibition around pristine PVA was observed. The prepared films proffered an effective antibacterial activity against contagious microorganisms that qualify them for food packaging and different biomedical applications.

Leveraging advances in chemistry to design biodegradable polymeric implants using chitosan and other biomaterials

The metamorphosis of biodegradable polymers in biomedical applications is an auspicious myriad of indagation. The utmost challenge in clinical conditions includes trauma, organs failure, soft and hard tissues, infection, cancer and inflammation, congenital disorders which are still not medicated efficiently. To overcome this bone of contention, proliferation in the concatenation of biodegradable materials for clinical applications has emerged as a silver bullet owing to eco-friendly, nontoxicity, exorbitant mechanical properties, cost efficiency, and degradability. Several bioimplants are designed and fabricated in a way to reabsorb or degrade inside the body after performing the specific function rather than eliminating the bioimplants. The objective of this comprehensive is to unfurl the anecdote of emerging biological polymers derived implants including silk, lignin, soy, collagen, gelatin, chitosan, alginate, starch, etc. by explicating the selection, fabrication, properties, and applications. Into the bargain, emphasis on the significant characteristics of current discernment and purview of nanotechnology integrated biopolymeric implants has also been expounded. This robust contrivance shed light on recent inclinations and evolution in tissue regeneration and targeting organs followed by precedency and fly in the ointment concerning biodegradable implants evolved by employing fringe benefits provided by 3D printing technology for building tissues or organs construct for implantation.

The framework of nanopesticides: a paradigm in biodiversity

Nanotechnology has imparted excellent substitutes in the area of agriculture for the management of insect pests without deteriorating the surrounding biota and thereby allows a more verdant environment. Particular idiosyncrasies have arisen in innovative nanoagrochemicals due to the viable applications of nanotechnology in a myriad of agricultural settings. Concerns have been raised about the need for novel products, therefore they have been predicted to have considerable potential to underpin the obligatory increase in worldwide food production in a sustainable manner. Conventional strategies like assimilated pest management employed in agriculture are inadequate and the application of chemical pesticides has pernicious impacts on the environment and mankind. There is a dire need to develop a repository of safe and propitious formulations to implement a regulatory paradigm for nanopesticides. Nanopesticides are well known in agriculture to reduce costs, improve the outcomes of agricultural products and enhance shelf life and nutrition. Much research has presented the innovation in a range of industrial domains that allows the improvement in the effective use of nanopesticides in water, nanocapsules for the delivery of biocides, nanosensors for the detection of pests, etc. Furthermore, the current consumption pattern of nanopesticides and their health repercussions has been elucidated. This much needed discussion will address the gap between the need for adequate control, environmental efficacy, associated benefits and the detrimental impacts of nanoagrochemicals.

Surface Functionalization of Graphene Based Polyhydroxyalkanoates Nanocomposites and Their Applications

Carbon nanotechnology coupled with polymer science has risen as an exceptionally encouraging device that could concurrently aggrandize all the biological and physical characteristics of polyhydroxyalkanoates. Nanoparticles with a grafted layer of polymers have become pervasive structures for implementation from the biomedical field to the production of sustainable energy. The design of carbon nanomaterials and surface modification delivers potentiality to invigorate logical endeavors in order to create a progressively ingenious community proficient of tackling the challenges. The inclusion of graphene in the matrix of polyhydroxyalkanoate manifests resistance against thermal degradation enhanced mechanical properties, lower gas permeability, and increment in electrical conductivity. Howbeit, several limitations restrict the competitiveness of graphene based polyhydroxyalkanoates with traditional synthetic nanocomposites or their implication as ideal biomaterials. To outmaneuver the drawbacks, modifications are a requisite to corroborate enhanced performance in distinct applications. Here, we detail the structure, function, review the functionalization routes, and discuss the current challenges looking forward toward future development directions.

Graphene and Its Derivatives: Fundamental Properties

The emerging science of graphene based engineered materials as functional surfaces for mechanics, electronics, sensing and other myriad applications is growing. This chapter brings state of the art graphene based materials to study the structure, preparation, properties, and implications. Derivatives studied in this chapter include graphene, graphene oxide, and reduced graphene oxide. The potential industrial implementation of the graphene synthesis methods is reviewed using the key criteria of cost, process condition, yield, scalability, product quality and environmental impact. In recent years nano graphene and its derivatives are finding their vast applications. Although, the properties are tremendous still there are some limitations as their toxicity is a major issue. Regardless of specific irregularities in various detailed test results and theories of toxicity mechanisms, results infer that the physicochemical properties, for instance, surface functionalities, coatings, charges, and structural imperfections of graphene may influence its in vitro/in vivo conduct just as its toxicity in biological frameworks. Henceforth, toxicity of graphene and its functionalized derivatives as a major issue is also dealt in later part of the chapter.

Graphene Reinforced Biopolymer Nanocomposites in Energy Storage Applications

Graphene reinforced biopolymer has lately empowered the dramatic enhancement of portable electronics and electric vehicles by proffering better means for storing electricity. To fulfill the consistently expanding demand for lightweight, compact electronic items, electric vehicles, brilliant lattices with sustainable power source combinations, the hybridization of graphene with several functions have been manifested. Being versatile and powerful procedure to essentially upgrade the performance of different energy frameworks in light of the fact that such hybridization can bring about synergistic impacts that consolidate finest qualities of incorporated segments and profer new capacities and properties. Consequently improving the charge/release efficiencies and abilities, vitality/power densities, and cycle life of these vitality stockpiling frameworks. The proposed chapter discusses the implication of graphene reinforced biopolymer nanocomposites for their utilization in supercapacitors, photovoltaic cells and lithium ion batteries. The modeling of Photovoltaic (PV) cell has been discussed in the later part of the chapter to examine the PV attributes and characteristics of PV cell. The future possibilities and bearings on the investigation of graphene reinforced biopolymer nanocomposites toward the design and development of practical, high-class, and even newly featured vitality stockpiling materials are discussed.

Graphene Based Biopolymer Nanocomposites in Sensors

The marvelous electrical, optical, mechanical and thermal characteristics coupled with high specific surface area of graphene label it as an appealing integrant for high-performance stimuli responsive smart materials. Typical graphene-based smart materials include mechanically exfoliated perfect graphene, chemical vapor deposited high-quality graphene, chemically modified graphene including, graphene oxide and reduced graphene oxide and their macroscopic assemblies or composites. The interaction of graphene based materials with biopolymers to deliver surprisingly beguiling electrical, mechanical, optical, thermal and sensing properties have received considerable attention. Biopolymer-based materials have the advantage of light weight, enhanced transparency, good elasticity, and biodegradability but are abided by drawback of poor mechanical strength, slow response and disappointing environmental stability. Howbeit, graphene fabricated biopolymers proffer propitious characteristics including sensitivity to a range of stimuli including gas molecules or biomolecules, pH value, mechanical flexibility, electrical and thermal conductivity to aid ceaseless promising development in sensor technology. In the chapter, we outline several graphene fabricated biopolymer nanocomposite-based smart sensors and their implication in chemical or strain sensors, actuators, gas sensors, detection of several biomolecules and their delivery. We also shed light on the sensing properties and debate about the challenges facing realization of their practicality.

Biopolymers in the automotive and adhesive industries

Innovation of sustainable materials is guided by the usage of synthetic materials and nonrenewable sources. Biopolymers are engineered for an array of applications because of their multidimensional characteristics, including biodegradability, biocompatibility, and excellent mechanical as well as optical properties. Adhesive technology can be directed to employ renewable materials that exhibit equal or outstanding performance in contrast to other conventional counterparts. Satisfactory life span and lightweight automobile parts as a way to facilitate car fuel utilization, and in this manner cut the outflow of ozone-depleting substances, will continue to prompt extended research into the practicality of polymers and their composites for use in cars. 

2020

An exploration of electrocatalytic analysis and antibacterial efficacy of electrically conductive poly (D-glucosamine)/graphene oxide bionanohybrid

The diversification of environment congenial and conservative nanocomposites is prestigious because of increasing contamination in biota. Poly (D-glucosamine), a natural biopolymer is contemplated as a promising biodegradable polysaccharide for various applications mainly in food packaging, bone substitutes, and water filtration. The drawback of poly (D-glucosamine) is nadir mechanical strength and high hydrophilicity which could be amended by the introduction of graphene oxide (GO) nanoparticles (shows excellent load transfer). Homogeneous distribution and well dispersion of GO nanoparticles in poly (D-glucosamine) matrix have been concluded by SEM investigation. Inclusions of 1% GO into the biopolymer matrix results in enhancement of 83.21 MPa of tensile strength in contrary to pristine poly (D-glucosamine). It can be elucidated that increment in properties is due to the crosslinking reaction takes place between the amine and epoxide moieties that exist within poly (D-glucosamine) matrix and GO respectively. The thermal stability of nanocomposites has been increased on addition of nanofiller confirmed by TGA analysis. The resultant nanocomposites were examined for antimicrobial screening against various contagious bacterial strains for packaging applications. Electrochemical characteristics and capacitive investigation of the composites were also studied using cyclic voltammetry and impedance (EIS) respectively. EIS elucidated that the nanocomposite modified electrode exhibited good capacitance behaviour with the Bode phase angle (-45°) which proves the candidates have good capacitive properties. The electrocatalytic properties are found to be diffusion controlled in alkaline medium with good electrical conductivity with low resistance. It is envisioned that the resultant bionanocomposite has potential applications in packaging industry.

Decoding glycans: deciphering the sugary secrets to be coherent on the implication

Neoteric techniques, skills, and methodological advances in glycobiology and glycochemistry have been instrumental in pertinent discoveries to pave way for a new era in biomedical sciences. Glycans are sugar-based polymers that coat cells and decorate majority of proteins, forming glycoproteins. They are also found deposited in extracellular spaces between cells, attached to soluble signaling molecules, and are key players in several biological processes including regulation of immune responses and cell–cell interactions. Laboratory manipulations of protein, DNA and other macromolecules celebrate the accelerated research in respective fields, but the same seems unlikely for the complex sugar polymers. The structural complex polymers are neither synthesized using a known template nor are dynamically stable with respect to a cell’s metabolic rate. What is more, sugar isomers—structurally distinct molecules with the same chemical formula—can be employed to construct varied glycans, but are almost impossible to tell apart based on molecular weight alone. The apparent lack of a glycan alphabet further reflects on an enduring question: how little do we know about the sugars? Evidently, glycan-based therapeutic potentials and glycomimetics are propitious advances for the future that have not been well exploited, and with a few conspicuous anomalies. Here, we contour the most notable contributions to enhance our ability to utilize the complex glycans as therapeutics. Diagnostic strategies concerning recurrent diseases and headways to address the challenges are also discussed. 

Carbon-based nanomaterials as novel nanosensors

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.