1.1 Introduction
Nanomaterials are utilized to develop optoelectronic devices, electronic devices, biosensors, nanodevices, and solar cells, due to their unique properties compared to their bulk forms such as miniaturized size, insulating nature, elasticity, electrical conductivity, mechanical strength, and high reactivity. They are classified based on geometry, morphology, composition, uniformity, and agglomeration. Geometrically, they are 0D, 1D, 2D, or 3D; morphologically, they are spherical, flat, needle, or random orientations (e.g., nanotubes and nanowires) with various shapes such as helices, belts, zigzags, with high aspect ratio and spherical, oval, cubic, and pillar, with low aspect ratio, and occurs in powder, colloidal, and suspension forms. Based on composition, nanomaterials are either a single-constituent material or a composite of several materials such as polymers, metals, ceramics, and alloys. Engineered nanomaterials can be synthesized by gas-phase processes, mechanical processes, vapor deposition synthesis, coprecipitation, etc., in an agglomerated state or dispersed uniformly in a matrix to their chemistry and electrostatic properties. Clusters or agglomerates are possible due to their surface energy, and it can be avoided with the proper chemical treatment to become uniform. Based on nanomaterial composition, they are classified as monometallic, bimetallic, trimetallic, metal oxide, magnetic, hybrid, semiconductor, composite, etc. Further, many nanomaterials can be classified based on their orientations, morphologies, and characteristics, including quantum dots (QDs), nanowires, nanotubes, nanofibers, nanofluids, nanobelts, nanoribbons, nanocapsules, nanosprings, nanosheets, and nanocomposites [1,2,3].
Nanomaterials are widely used nowadays for various applications in various domains such as biomedical, environmental, and agricultural. It was recently reported that gold nanomaterials that exhibit unique optical properties could be utilized in colorimetric sensors for a wide range of applications [4]. Further, Zhou et al. (2020) reported carbon nanofibers utilizing biomedicine, environmental science, energy storage, and materials science. These functional nanomaterials are being used as environmental adsorbents, supercapacitors, batteries, fuel cells, solar cells, sensors, biosensors, antibacterial materials, tissue engineering, and sharp memory materials [5]. Moreover, recently bioactive proteins and nanomaterial-based advanced version of biosensors were fabricated for the point-of-care diagnosis, environmental monitoring, and food safety [6]. Further, it is well established that nanomaterials (nano-ferric oxide, carbon nanotubes (CNTs), graphene oxide (GO), fly ash, and steel fibers), when utilized in the concrete, result in improved durability and sustainability by enhancing mechanical features, which offer them a variety of applications in the field of mechanical engineering [7].
This chapter of the book entitled āNanomaterials in Bionanotechnology: Fundamentals and Applicationsā highlights the basic utility of the nanomaterials in the biomedical, environmental, and agricultural domains along with the current trends and prospects. Further, this book will elaborate on nanomaterial classification, synthesis, and properties in Chapter 2, followed by Chapter 3 about biomaterialsā biological synthesis. Furthermore, the chemical aspects in the fabrication of various technologies based on nanomaterial are discussed in Chapter 4. Chapter 5 deals with the emerging nanocomposites and their multifunctional applications, followed by Chapter 6, which deals with the current nanomaterial scenario in the environmental, agricultural, and biomedical domains. Chapter 7 of this book deals with nanomaterials for environmental hazard analysis, monitoring, and removal, and Chapter 8 deals with the recent agriculture trends based on nanomaterials. Further, Chapter 9 and Chapter 10 deal with the role of nanomaterials in the food sector, Chapter 11 and Chapter 12 deal with the role of nanomaterials in disease diagnosis, and the last chapter of this book, Chapter 13, deals with the potentialities of nanomaterials as nanomedicine for the treatment of various types of diseases.
1.2 Biomedical Applications
Nanomaterials have potential biomedical applications (Figure 1.1) using either inorganic or organicāinorganic materials with unique properties such as physicochemical, optical, magnetic, and stimuli-responsive at the 1- to 100-nm scale for drug delivery, targeted drug delivery, gene delivery, bioimaging, biosensors, cell labeling, and photoablation therapy [8,9,10,11]. Dai et al. (2020) reported novel methods based on nanomaterials for the early diagnosis of hepatocellular carcinoma, a liver cancer known worldwide, as its early detection and treatment can improve patientsā lives [12]. Koo et al. (2020) reported magnetic nanomaterial-based electrochemical biosensors for selective detection of cancer biomarkers associated with cell surface proteins of tumor cells and their nucleic acids [13]. Nuclear medicine imaging is a diagnostic approach for cancers to detect gamma rays. Recently, Ge et al. (2020) reported nanomaterial-based radioactive tracers for early and accurate diagnosis of cancers [14]. In modern biomedical sciences, exosomal cancer biomarkers are known for the early diagnosis and treatment of cancer. Shao and Xiao (2020) reported nanomaterial-based optical biosensors to detect exosomal cancer biomarkers [15]. Khan et al. (2020) reported the nanozyme, next-generation biomaterials in biomedical and industrial biosensing and therapeutic activities [16]. Furthermore, Zhang et al. (2020) reported the next-generation artificial enzymes used in detection, diagnosis, and therapy [17]. Li et al. (2020) reported nanozyme-based composite materials, an intelligent and multifunctional therapeutic agent for preventing or resisting bacterial biofilms [18]. Yang et al. (2020) reported details about bacterial infection-related diseases that are causing health problems globally as the use of antibiotics is causing antibiotic resistance and for overcoming these problems, nanozymes, inorganic nanostructures with enzymatic activities, have shown great potential owing to its excellent antimicrobial properties and negligible biotoxicities [19]. Johnson et al. (2020) reported graphene nanoribbons, strips of single-layer graphene, amphiphilic in nature, and having unique properties and high surface area, can be used in biomedical applications such as in gene therapy, drug delivery, antimicrobial therapy, anticancer therapy, photothermal therapy, bioimaging, and sensing [20]. Li et al. (2020) reported selenium-containing nanomaterials, which exhibit good biocompatibility and can be used as redox stimuli, drug delivery carriers, and anticancer drugs for the treatment of cancer, as it is the global health problem and causes economic burden worldwide [21]. Further, Joshi e...
