eChapters

Introduction

Nanofertilizers are products of nanotechnology that are created or modified from conventional fertilizers, bulk fertilizer materials, or plant extracts. They use different methods such as chemical, physical, mechanical, or biological processes to produce nanosized particles that can enhance soil fertility, crop productivity, and quality (KhetiGaadi 2022). Nanofertilizers have a size range of 0.1–100 nm, which is similar to the size of plant cell wall (20 nm), making them easier to be absorbed by plants (Tiwari 2022).

Introduction 
There are terrible consequences of climate change for the planet and all human endeavors. According to statistics provided by the Bureau of Social and Economic Affairs which indicate the rate of increase in global human population is frightening; by 2050 (Rebello et al., 2010), the population is expected to surpass 9.8 billion people. Thus, throughout the course of 30 years from now, the community will encounter several issues that will threaten the survival of the majority of living things on Earth. These issues include the shortage of energy, global warming, greenhouse effects, poisonous gas emissions, and abrupt changes in the environment. The usage of natural fuels as our primary source of energy has raised issues in international scientific organizations, which are working to address one of the key causes of these problems (Zhu et al., 2016). The one method to address the issue is to find an environmentally sustainable fossil fuel replacement that can meet the world’s expanding energy needs (Dincer et al., 2000). Biofuels are one of the viable options and it is an alternative to fossil fuels since they are affordable and harmless to the surroundings (Ma et al., 2014). Various countries around the world are utilizing them to partially substitute the consumption of natural fuels. For example, Brazil uses sugarcane, while parts of Asia and Europe primarily rely on palm oil for production. In the case of biofuels made from microalgae, the United States, Brazil, China, and Japan are the biggest producers. Currently, biofuel generation predominantly relies on three distinct generations of raw organic resources, as outlined by Zhu et al. (2016) and Brennan et al. (2016). These groups represent different sources and technologies utilized to produce biofuels on a global scale. Biofuels classified as first-generation are those derived from feedstocks that are suitable for human intake, such as wheat, sugarcane, maize, palm oil, and sugar beet. Biofuels classified as secondgeneration are derived from lignin and cellulosic feedstock, which consists of non-food crop portions including husks, stems, and leaves that are often thrown away (Kalnes et al., 2007 ; Naik et al., 2010 ; Zhu et al., 2016). However, these biofuel sources can partially fulfill the world’s energy demands. One method to overcome this limitation involves third-generation biofuels, which are generated by cultivating single-celled photosynthetic microorganisms capable of converting carbon dioxide and sunlight into biomass and lipid molecules used in biofuel production (Abomohra et al., 2017).

Nanomaterials are a field which takes a materials science-based approach to nanotechnology. It studies materials with morphological features on the nanoscale, and especially those which have special properties stemming from their nanoscale dimensions. Nanoscale is usually defined as smaller than a one tenth of a micrometer in at least one dimension, though this term is sometimes also used for materials smaller than one micrometer.

An aspect of nanotechnology is the vastly increased ratio of surface area to volume present in many nanoscale materials which makes possible new quantum mechanical effects, for example the “quantum size effect” where the electronic properties of solids are altered with great reductions in particle size. This effect does not come into play by going from macro to micro dimensions. However, it becomes pronounced when the nanometer size range is reached. A certain number of physical properties also alter with the change from macroscopic systems. Novel mechanical properties of nanomaterials are a subject of nanomechanics research. Catalytic activities also reveal new behaviour in the interaction with biomaterials.

Nanomaterials have emerged as promising candidates for revolutionizing sensing and detection technologies, offering unprecedented capabilities in sensitivity, selectivity, and miniaturization. The current chapter provides a concise overview of recent advancements in the utilization of nanomaterials for sensing and detection applications. It encompasses a diverse range of nanomaterials, including nanoparticles, nanotubes, and nanowires, each exhibiting unique properties that enable enhanced performance in sensing applications. The integration of nanomaterials into sensing platforms has demonstrated remarkable progress in various fields, such as environmental monitoring, healthcare diagnostics & security applications.

This section explores how nanoparticles have a significant influence on sensing and detection, explaining how they have revolutionized analytical capabilities. Our trip through many kinds of nanomaterials, such as metal nanoparticles, semiconductor nanomaterials, and carbon-based structures, aims to explore their distinct features and how they might be used for novel sensing methods. The intricacies behind sophisticated sensor technologies are clarified through an examination of plasmonic sensing, quantum dot applications, and conductive nanomaterial responses. In order to improve selectivity, the chapter emphasises surface modifications and biomimetic coatings as key components of strategic functionalization techniques.

Nanomedicine, an interdisciplinary field at the intersection of nanotechnology and medicine, has emerged as a promising avenue for addressing complex health challenges. One area of significant interest is the application of nanotechnology in maintaining and improving gut health. This chapter provides a concise overview of the current state of research in nanomedicine's role in promoting gastrointestinal well-being.

Nanoparticles, with their unique physicochemical properties, offer novel approaches for targeted drug delivery, imaging, and diagnostics in the gastrointestinal tract. Engineered nanoparticles can navigate the harsh conditions of the digestive system, delivering therapeutic agents precisely to the intended sites within the gut.

Nanomedicine is the medical application of nanotechnology. The approaches to nanomedicine range from the medical use of nanomaterials, to nanoelectronic biosensors, and even possible future applications of molecular nanotechnology. Current problems for nanomedicine involve understanding the issues related to toxicity and environmental impact of nanoscale materials.

Nanomedicine research is receiving funding from the US National Institute of Health. Of note is the funding in 2005 of a five-year plan to set up four nanomedicine centers. In April 2006, the journal Nature Materials estimated that130 nanotech-based drugsanddeliverysystems were being developed worldwide.

Nanoparticle characterization is necessary to establish understanding and control of nanoparticle synthesis and applications. Characterization is done by using a variety of different techniques, mainly drawn from materials science. Common techniques are electron microscopy (TEM, SEM), atomic force microscopy (AFM), dynamic light scattering (DLS), x-ray photoelectron spectroscopy (XPS), powder X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF),ultraviolet-visible spectroscopy and dual polarisation interferometry.

Whilst the theory has been known for over a century (see Robert Brown), the technologyfor Nanoparticle trackinganalysis (NTA) allows direct tracking of the Brownian motion and thismethodtherefore allows the sizing of individual nanoparticles in solution.

Nanomaterials, a cornerstone of nanotechnology, encompass a broad array of particles showcasing remarkable properties and diverse applications. This chapter outlines the classifications and applications of various nanomaterials, including organic, semiconductor, metal, metal oxide, and carbon-based nanoparticles. Each type offers unique characteristics, such as biodegradability, optical and electrical properties, making them valuable in fields like drug delivery, electronics, and catalysis. Furthermore, this study focuses on the interactions of nanoparticles with living organisms, emphasizing their impact on immune systems across plants, invertebrates, and humans. 

Bipolar plates (BPPs) are essential components of proton exchange membrane fuel cells, performing functions related to gas distribution, current collection, thermal management, water management, and cell separation. This chapter examines conventional and advanced materials used for BPPs, with particular emphasis on nanoparticle-enhanced composite systems. The incorporation of nanoparticles can improve electrical and thermal conductivity while reducing weight and supporting environmental sustainability. Materials, synthesis and fabrication techniques, and additive manufacturing approaches are discussed. The chapter also considers cost and scalability because these factors influence the wider commercialization of fuel-cell technologies. Nanoparticle-reinforced composites are presented as promising lightweight alternatives for sustainable energy applications.

14.1 Introduction

The fast growing field of nanotechnology presents great potential to influence various sectors in the areas of energy, environment, agriculture, health care and consumer goods. To overcome the demanding need of nano-based applications, various strategies to synthesize nanoparticles have been attempted. The major focus is to synthesize nanoparticles of desirable properties such as shape, size and compositions. Various strategies have been employed to synthesize nanoparticles. Foremost among these are physical and chemical methods which include sol-gel technique, solvothermal synthesis, chemical reduction, laser ablation and inert gas condensation. But altogether they suffer from process limitations like difficulty in controlling experimental conditions, feeble reproducibility, polydispersity, costly instrumentation and recovery as well as energy intensive and eco-hazardous processes. However, various factors like cost, speed, efficiency, biocompatibility etc. are still not concerned. Thus, finding a balance between scalability, price and applicability is still a true challenge. These limitations can be potentially overcome by using biological methods for nanoparticle synthesis.

Agri-nanotechnology is a new branch of biology that has originated due to the compatibility of nanosized inorganic and organic particles with biological functions. Based on enhanced effectiveness, the new age drugs are nanoparticles of polymers, metals, or ceramics, which can facilitate several biological applications. Plant diseases are caused by pathogens including fungi, bacteria, mycoplasma, viruses and viroids, nematodes, parasitic plants, and protozoa. 

Introduction

Nanotechnology is a scientific and technological field that manipulates matter at the nanoscale to create, design, characterize, and use structures, systems, and devices with novel properties (Sattler 2016). Nanoparticles are one of the most important products of nanotechnology, as they exhibit different features from their bulk counterparts due to their size and shape (Sabir et al., 2014). Nanoparticles have applications in various disciplines, such as materials science, medicine, agriculture, physics, and chemistry.

Synthesis of nanoparticulate metal composites (NMCP) presents a multitude of advantages compared to conventional dosage forms. Acne, a multifactorial skin condition, predominantly involves the pilosebaceous unit and is primarily caused by bacterial species such as Propionibacterium acnes and Acne vulgaris. A staggering 95% of the global population is afflicted by acne. Leveragitng NMCP strategies holds immense promise for innovating novel, efficacious, and low-dose treatments for managing acne. This review delves into various nanotechnological methodologies tailored for effectively addressing acne. Methods: This review encompasses recent advancements pertaining to NMCP carriers aimed at treating acne.

Introduction

Nanopesticides are pesticides that use nanomaterials or nanotechnology to improve their effectiveness and safety in agriculture. Nanomaterials are materials that have at least one dimension between 1 and 200 nm. Nanomaterials have different properties than their bulk counterparts, such as higher surface area, reactivity, and mobility. Nanopesticides can be formulated in various ways, such as nanosized active ingredients, molecular active ingredient nanocarrier complexes, or active ingredients encapsulated or coated by nanomaterials (Deka et al., 2021; Xu et al., 2022).

Introduction

Plastic is the main component of environmental pollution, as it is continuously disposed of into the environment in substantial quantities. Since the creation of the first plastic polymer in the mid-twentieth century, plastic production has increased dramatically, from 1.5 million tons in 1950 to 280 million tons of plastic produced in 2011, with an annual growth rate of 8.7 % (Europe, 2017). By the 2050s, humans are expected to generate 26 billion tons of plastic waste, four times the current levels of plastic waste globally. Due to this serious concern, the United Nations has prioritised plastic waste and its management as one of the fundamental environmental concerns in its 2030 Agenda for Sustainable Development. Plastics appear in the environment in visible and invisible forms. The visible form refers to common scenes, such as bags “flying” on tree branches, PET bottles floating in rivers, lakes, and seas or face masks we use daily. The visible form of plastic in the environment is an aesthetic mockery and a reminder of the socially indiscriminate reception of all offers from the petrochemical industry. The invisible form of plastics is called nanoplastics.

The hazardous toxic metals like cadmium (Cd), arsenic (As), mercury (Hg), lead (Pb), and chromium (Cr), which have detrimental health effects, are naturally discharged into the atmosphere in various ways viz., industrial wastes, anthropogenic sources, etc. Heavy metal pollution of the atmosphere has become a frightening ecological concern that has created serious threats to the ecosystem. These metals have been identified as group I, human carcinogens due to their persistence in the surroundings and bio-magnification in biological systems. Thus, the removal of heavy metals from the atmosphere becomes a serious matter from the biological and environmental point of view. In the past following techniques adoptedfor toxic heavy metals remediation were classified are bioadsorption, ion exchange, membrane filtration, flotation, and solvent extraction techniques.

Nanotechnologies are being spoken of as the driving force behind the new industrial revolution. The mass production of these nano materials and their applications mean a dramatic increase of workers dealing with Engineered Nano Materials (ENM) and becoming possibly exposed to resulting hazardous effects and increased environmental burden of the environment due to the leaks of these materials from industrial processes. It is, hence, essential to consider the importance of ENM safety and their new applications and understand that it is important for these materials and products to be safe to enable successful promotion of nanotechnology for useful applications (Eman M Osman, 2019). 

Characterization Tools: Microscopy

Nanosensors are any biological, chemical, or sugery sensory points used to convey information about nanoparticles to the macroscopic world. Their use mainly include various medicinal purposes and as gateways to building other nanoproducts, such as computer chips that work at the nanoscaleand nanorobots. Presently, there are several ways proposed to make nanosensors, including Top-down and bottom-up design, top-downlithography, bottom-upassembly, and molecular self-assembly.

Predicted applications

Medicinal uses of nanosensors mainly revolve aroundthe potential of nanosensors to accurately identify particular cells or places in the body in need. By measuring changes in volume, concentration, displacement and velocity, gravitational,electrical, and magneticforces, pressure, or temperature of cells in a body, nanosensors may be able to distinguish between and recognize certain cells, most notably those of cancer, at the molecular level in order to deliver medicine or monitor development to specific places in the body. In addition, they may be able to detect macroscopic variations from outside the body and communicate these changes to other nanoproducts working within the body.