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COVID-19 infections and severe acute respiratory syndrome (SARS) have caused an unprecedented health crisis across the globe with numerous deaths, as well as causing a tremendous economic crash worldwide.

Aim: The functionalization and characterization of antibacterial nanoceria with folic acid (FA) and elucidation of their in vivo wound-healing application. Materials & methods: Functionalization of nanoceria were done with FA using a chemical method and their antibacterial activity, cellular biocompatibility and in vivo wound-healing application were evaluated. Results: The functionalization of nanoceria with FA was done with 10–20 nm size and -20.1 mV zeta potential. The nanoformulation showed a bacteriostatic effect along with biocompatibility to different cell lines; 0.1% w/v spray of FA-nanoceria demonstrated excellent wound-healing capacity within 14 days in a Wister rat model. Conclusion: The antioxidant and reactive oxygen species scavenging activity of the FA-nanoceria make it a promising therapeutic agent as a unique spray formulation in wound-healing applications.

In this review we highlight the detrimental effect of numerous environmental factors potentially implicated in the etiology, prevalence and inflection of polycystic ovarian syndrome (PCOS) in woman population. PCOS is a heterogeneous multifaceted disease of woman emanating infertility, abnormal fetal growth and irregular menstruation. Precisely, the leading environmental factors we discuss include oxidative stress, environmental toxins, lifestyle, nutrition and heavy metal elements causing the onset of PCOS. Research evidences explore that environmental toxins can potentially induce the oxidative stress through (reactive oxygen species) ROS generation, thereby disrupting the reproductive health system. Additionally the synergistic influence of certain dietary supplements and weight loss in obese women has also deliberated. The features of key nutritional factors in preventing or mitigating the growth of PCOS as well as its associated with other metabolic disorder have scrutinized. Finally, further research in these avenues is highly admirable since global scenario of PCOS is remarkably crucial pointer of socioeconomic, environmental and epigenetic factors that possibly leads to adverse health effects in future generations of the world.

Graphene has gained recognition within the research community owing to its fascinating properties in the plethora of energy-related applications. The properties include high thermal and electrical conductivity, greater mechanical strength, optical translucency, intrinsic flexibility, massive surface area, and distinctive two-dimensional structure. Graphene is highly competent in enriching the functional performance, endurance, stability of many applications. However, still ample research diversity will be desirable for graphene commercialization in energy sectors. This intuitive scrutinization reconnoitered the talented employment arena of graphene in various energy storage and harvesting fields. The amplification of the versatile applicability of graphene and comprehensive perception regarding pros and cons of graphene based nanohybrids could critically pinpoint current constrictions by upgrading its characteristics performance. The chapter provides an insight into the unique features of graphene and amalgamation with nanomaterials to enlighten its various energy-related applications, including supercapacitors, biosensors, solar cells, batteries. With the breakneck miniaturization in the employment of graphene in various energy-relevant applications, it is crucial to epitomize align="center" and figure out the progressive momentum of graphene and its nanohybrids in several energy-related application territories.

Coal being the most abundant natural resource is used worldwide and shows graphite-like clusters. Here, for the first time, we report an innovative and cost-effective oxidative functionalization approach, followed by an acid-free and oxone oxidant-assisted solvothermal synthesis of graphene quantum dots from coal. This method involving the oxidative functionalization of coal was performed through the heat treatment of nitric acid, followed by an acid recovery process. Indeed, the solvothermal method used was entirely free from the utilization of strong acids, and involved a simple, eco-friendly, and salt-free purification process with a high production yield (∼45%). Due to the synergistic synthesis technique, our developed GQDs were found to exhibit a strong blue photoluminescence (PL) characteristic with a significantly high quantum yield (∼14.42%). High-resolution transmission electron microscopy (HRTEM) images indicated that the nanocrystalline GQDs had a uniform and narrow particle-size distribution in the range of 2.5–5 nm. The anticancer efficacy of the as-synthesized GQD nanomaterial was validated through cellular morphological pattern analysis and DAPI-staining images of neuroblastoma cells and breast cancer cells. In addition, the alteration of the mitochondrial membrane potential was scrutinized using JC-1 micrographs. Interestingly, the RITC-tagged GQDs showed cellular internalization within breast cancer cells. The robust functionality, luminescence stability, nanosecond lifetime, biocompatibility, and low toxicity of our developed GQDs suggest they could be promising probes for cancer therapeutic applications. This study unveils new opportunities for the sustainable production of GQDs with novel attributing features due to the easily availability of the raw materials, their cost-effective production, and fascinating photoluminescence property.

In this study, chemical (S1) and green (S2) Copper Oxide nanoparticles (NPs) were synthesized to determine their biodistribution and toxicokinetic variances in vitro and in vivo. Both NPs significantly released Copper ions (Cu) in lymphocytes and were primarily deposited in the mononuclear phagocyte system (MPS) such as the liver and spleen in mice. In particular, S2NPs seemed to be prominently stored in the spleen, whereas the S1NPs were widely stored in more organs including the liver, heart, lungs, kidney and intestine. The circulation in the blood and fecal excretions both showed higher S2NPs contents respectively. Measurements of cell viability, Hemolysis assay, Reactive Oxygen Species (ROS) generation, biochemical estimation and apoptotic or necrotic study in lymphocytes after 24 h and measurements of body and organ weight, serum chemistry evaluation, cytokines level, protein expressions and histopathology of Balb/C mice after 15 days indicated significant toxicity difference between the S1NPs and S2NPs. Our observations proved that the NPs physiochemical properties influence toxicity and Biodistribution profiles in vitro and in vivo.

Nanostructured conducting polymers are known to function as electroactive materials in sensor devices for adsorption and detection of different analytes. For the purpose of dopamine (DA) detection and CO2 gas adsorption we have prepared nanostructured polypyrrole (PPY) with the help of sodium cholate as surfactant. X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), Scanning electron microscopy (SEM), Transmission electron microscopy (TEM) analyses and Brunauer–Emmett–Teller (BET) measurement have been done for the characterization of nanostructure and morphology of the prepared PPY. From the sorption measurement, it is observed that the rodlike PPY structures show highest N2 uptake (91.6 mL g−1) along with appreciable surface area (85.81 m2/g) and porosity (2.53 and 4.51 nm) values. It is also observed that the maximum uptake of CO2 is 173.885 mL g−1 at 195K for the PPY synthesized without any surfactant. Electrochemical characterization of PPY modified glassy carbon electrode (GCE) was done with impedance and cyclic voltammetry experiments. DA sensing in presence of ascorbic acid, uric acid and glucose was done by LSV technique. The PPY modified electrode exhibits sensitivity values of 0.301 and 0.19 μA μM−1 cm2 over two ranges of detection limits of 0.09–0.56 and 10–50 μM for dopamine, respectively (signal/noise = 3).

Nanotechnology has acquired an immense recognition in cancer theranostics. Considerable progress has been made in the development of targeted drug delivery system for potent delivery of anticancer drugs to tumor-specific sites. Recently, multifunctional nanomaterials have been explored and used as nanovehicles to carry drug molecules with enhanced therapeutic efficacy. In this present work, graphene oxide quantum dot (GOQD) was conjugated with folic acid functionalized chitosan (FA-CH) to develop a nanocargo (FA-CH-GOQD) for drug delivery in cancer therapy. The synthesized nanomaterials were characterized using Fourier transform infrared spectroscopy, ultraviolet-visible spectroscopy, scanning electron microscopy, transmission electron microscopy, and dynamic light scattering. Photoluminescence spectroscopy was also employed to characterize the formation of GOQD. To validate the efficacy of FA-CH-GOQD as nanocarriers, doxorubicin (DOX) drug was chosen for encapsulation. The in vitro release pattern of DOX was examined in various pH ranges. The drug release rate in a tumor cell microenvironment at pH 5.5 was found higher than that under a physiological range of pH 6.5 and 7.4. An MTT assay was performed to understand the cytotoxic behavior of GOQD and FA-CH-GOQD/DOX. Cytomorphological micrographs of the A549 cell exhibited the various morphological arrangements subject to apoptosis of the cell. Cellular uptake studies manifested that FA-CH-GOQD could specifically transport DOX within a cancerous cell. Further anticancer efficacy of this nanomaterial was corroborated in a breast cancer cell line and demonstrated through 4',6-diamidino-2-phenylindole dihydrochloride staining micrographs.

Synthesis of graphene composites are ubiquitous, but efficient method of synthesis of graphene composites are rare. Herein, in this work we describe a single step method using pressure cooker for the synthesis of reduced graphene oxide (RGO)/SnO2 nanocomposite using graphene oxide (GO) and tin chloride (SnCl2·2H2O) as the starting materials. The RGO/SnO2 nanocomposite was characterized by Thermo-Gravimetric Analysis (TGA), X-ray Diffraction (XRD), Fourier-Transform infrared spectroscopy (FTIR), UV–visible spectroscopy (UV–vis), Raman spectroscopy, Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM) and Photo Luminescence spectroscopy (PL). The size of the SnO2 nanoparticles deposited on the graphene sheets is less than 10 nm. The obtained RGO/SnO2 nanocomposite showed high capacity and excellent efficiency in optical applications. First principle calculations reveal that RGO/SnO2 nanocomposite attributes a strong electronic interaction between the tin oxide and graphene. To explore the potential optical capability of reduced graphene oxide (RGO)/SnO2 nanostructure, three plausible configurations were relaxed based on the estimated relative energies. The overall study projected this nanohybrid material for potential applications in semiconductor industries.

A nanocomposite of activated carbon (AC) and graphene oxide (GO) has been used as adsorbent of methylene blue (MB) dye from solution. FTIR spectroscopy, XRD, SEM imaging, size and zeta potential analysis of the nanocomposite material indicate retention of the essential features of both the components responsible for adsorption. Parameters like pH, temperature, adsorbent and salt concentrations, etc. were varied to optimize the adsorption. A very significant increase in adsorption by this nanocomposite, compared to those arising from the individual components, could be observed, resulting in an adsorption capacity of up to 1000 mg/gm. Fit of the data to kinetic equations gave rate constants for the process. Good fits to both Langmuir and Freundlisch isotherms indicated that the contribution of electrostatic attraction between the charged groups present in the composite and dye molecules, as well as the adsorption through AC surface pores both play significant roles. The synergy of these two different mechanisms yields the extraordinarily large adsorption capacity. This factor, together with the cheapness of the material, and its selectivity towards cationic dyes suggest its practical importance for water decontamination.

Conducting polymer-noble metal nanocomposites have attracted considerable interest as electrochemical sensors because they provide better sensing responses to different analytes. We report the synthesis of rod like polypyrrole (PPY)-Ag nanocomposite using sodium cholate as soft-template for sensing nanomolar concentration of dopamine (DA). The nanocomposites were characterized by employing FT-IR, XRD, scanning and transmission electron microscopic analysis. Electrochemical impedance spectroscopy and cyclic voltammetry experiments were performed for electrochemical characterization of the PPY-Ag nanocomposite deposited on glassy carbon electrode (GCE). Electrochemical detection of DA using this nanocomposite deposited on GCE was done following linear sweep voltammetry. The PPY-Ag nanocomposite deposited electrode showed improved sensitivity value of 8.22 mAμM−1 for DA and a detection limit of 0.00005 μM. Biocompatibility assay of the developed PPY-Ag nanocomposites have exhibited less toxicity to mouse fibroblast cell even in comparison to that of PPY without silver. Antimicrobial property of the PPY-Ag nanocomposites towards E.coli and S. Aureus have also been observed.

Nanostructured conducting polymer provides higher surface area for analyte vapor sensing. This investigation aims to synthesize rod-like polypyrrole (PPY) silver nanocomposite tailored by sodium cholate surfactant as soft template for sensing of acetone vapor. During oxidative polymerization of pyrrole by ferric chloride Ag nanoparticle gets deposited on PPY by simultaneous reduction of silver nitrate. The crystal structure, surface morphology and nature of interfacial interactions between the two components of the prepared PPY-silver nanocomposite (PPY-Ag) are analyzed by standard characterization techniques. The Ag nanoparticles deposition on rod-like PPY increases with increasing silver nitrate concentration up to an optimum level. The PPY-Ag nanocomposites show chemiresistive type dynamic sensing responses toward methanol, ethanol and acetone vapor in a mixture with air. A comparative evaluation of typical vapor sensing parameters (% response, response time, recovery time, reproducibility, and selectivity) of PPY-Ag nanocomposite sensor obtained for different volatile organic compounds with those of the pristine PPY sensor is reported. Interestingly, the rod-like PPY-Ag nanocomposite is found to selectively sense acetone vapor showing better % response than that of the other analytes, viz., methanol, ethanol, propanol, water vapor and formaldehyde. The differences in their responses for the different analytes and the selectivity toward acetone vapor are established by considering the difference in their interactions with the nanocomposite.

In this work, we report the development of a cross-linked bio-composite consisting of graphene oxide, potato starch, cross-linker glutaraldehyde and its application to adsorption of the industrial dye, methylene blue, from aqueous solution. The inexpensiveness, non-hazardous nature and easy bio-degradability are the major reasons for the selection of starch material as one of the components of the bio-composite. The bio-composite has been characterized by FTIR, SEM, XRD, particle size and zeta potential analysis. The FTIR analysis reveals the nature of the binding sites and surface morphology of the bio-composite can be understood through SEM. The auto-phase separability of the adsorbent i.e., the precipitation of the adsorbent without any mechanical means is another factor which makes this particular material very attractive as an adsorbent. Parameters like adsorbent dosage, pH, temperature, rotation speed and salt concentration have been varied to find out the suitable dye adsorption conditions. Furthermore, the time dependence of adsorption process has been analyzed using pseudo-first and pseudo-second order kinetics. The adsorption isotherms have been constructed to suggest convincing mechanistic pathway for this adsorption process. Finally, desorption studies have been successfully performed in 3 cycles, establishing the reusability of the material, which should allow the adsorbent to be economically promising for practical application in wastewater treatment.

A promising green biosensing material, nano-cerium oxide (CeO2) decorated reduced graphene oxide (RGO) nanohybrid reinforced chitosan (CS) nanocomposite has been synthesized as a transducer phase for the effective immobilization of glucose oxidase (GOx) enzyme. CeO2 nanoparticles were grown on the RGO nanosheet by facile hydrothermal treatment. The effective growth of synthesized nano-CeO2 on the RGO was evident from X-ray diffraction, scanning electron microscopy and transmission electron microscopy and Raman analysis. Morphological studies confirmed the effective immobilization of GOx on the chitosan nanocomposites modified FTO electrode. The electrocatalytic response of the GOx/nano-CeO2–RGO/CS/FTO bioelectrode was investigated using electrochemical impedance and cyclic voltammetry studies. The obtained results indicate that as compared with bare CeO2 nanoparticles and RGO, the nano-CeO2/RGO nanohybrid shows significant electrochemical activity and provides an adequate microenvironment for effective enzyme immobilization due to the excellent synergism between the CeO2 nanoparticles and RGO nanosheet. Scheme 1: Schematic diagram of graphene nanohybrid reinforced Chitosan nanocomposite modified biosensing matrix.

A candid approach to analyze the performance characteristics of phenyl phosphonate-functionalized zirconium oxide and pure zirconium oxide (ZrO2) fillers reinforced chitosan nanocomposites and their suitability as a potential biomaterial for the development of transducer surface in biosensing device has been investigated in this communication. Functionalization of ZrO2 has been carried out using sulfophenylphosphonate which was confirmed using Fourier transform infrared spectrographs. The electrostatic intercalation of chitosan with filler particles was monitored using electrochemical impedance analyzer which exhibits lowest bulk resistance which is highly effective for ionic switching. Incorporation of zirconium sulfophenylphosphonate (ZrSP) the ionic conductivity of the chitosan film attained a value of 1.2 × 10−6 S/cm as compared to the unmodified one which is a prefeasibility work for the fabrication of biosensing platform. Variation in performance characteristics has been evaluated through morphological and thermal characterization. TGA and DSC analysis reveal that the thermal stability and decomposition temperature of the nanocomposites were improved by the addition of reinforcing filler particles. XRD and SEM and TEM results support the above assumption. The continuous alignment of the proton transfer channels of the nanocomposites was thoroughly investigated by AFM analysis which revealed phase morphology for improved enzyme entrapment. Further, surface functionalized nanofillers result considerable increment of mechanical properties in terms of elastic modulus and tensile stress.

The present study summarizes the designing of a green transducer phase based on nano-cerium oxide (CeO2) decorated reduced graphene oxide (RGO) reinforced chitosan nanocomposites as an effective enzyme immobilizer and bio-sensing matrix for glucose analyte. Also, it scrutinizes the biocompatibility and cell viability of the synthesized nanohybrid with human fibroblastic macrophage cell line. CeO2 nanoparticles (NPs) were successfully grown on graphene nanosheet in the presence of cationic surfactant followed by facile hydrothermal treatment. The eventual growth of synthesized CeO2 nanocrystals on the graphene layer was confirmed from X-ray diffraction (XRD), transmission electron microscopy (TEM) and Raman analysis. The biocompatibility of the synthesized nanohybrid was also evident from the MTT assay. Glucose oxidase (GOx) was employed on the green polymer nanocomposites modified FTO electrode to fabricate an enzymatic bioelectrode. The electroanalytical response of the GOx/nano-CeO2/RGO/CS/FTO bioelectrode towards electrooxidation of glucose analyte was investigated by electrochemical impedance (EIS) and cyclic voltammetry (CV) study. The resulting biosensor exhibited a good electrochemical response to glucose within the linear detection range of 0.05-6.5 mM with a low detection limit of 2 μM and a sensitivity of 7.198 μA mM(-1) cm(-2). The bioelectrode also showed good shelf life (~10 weeks) and negligible interfering ability under controlled environment. The obtained results indicate that nano-CeO2/RGO nanohybrid based chitosan nanocomposites achieve a biocompatible biosensing platform for effective enzyme immobilization due to the excellent synergistic effects between the CeO2 nanoparticles and graphene sheet.

Graphene, a single sp2 bonded carbon, is now a burgeoning interest with various fascinating properties in a large number of biomedical applications. Consequently, the impact of graphene-based functional nanohybrid and its potential risk to human health have raised considerable public concerns. In this present study, we have synthesized cerium oxide ( CeO 2) anchored reduced graphene oxide (RGO) nanohybrid and a detailed study on its nanotoxicity profile has also been scrutinized. To confirm the efficient synthesis of nano- CeO 2/RGO nanohybrid, the systematic characterization has been carried out using FTIR, Raman and UV-Vis spectroscopic analysis. The successful imprint of CeO 2 nanoparticles (NPs) on RGO nanosheet was also evident from the scanning electron microscopy (SEM) and transmission electron microscopy (TEM) micrographs. A dose-dependent in vitro nanotoxicity of the nanohybrid has been assessed by using monocyte macrophage cells-Raw264.7 and colon cancer cells-HCT116 as compared with RGO and CeO 2. The results conferred that as compared with single nanostructures (RGO or CeO 2), nanohybrid showed excellent biocompatibility and no such prominence morphological alteration of the cell structure. Moreover, after exposure of different nanomaterials to HCT116 cells, the possible cellular interaction was investigated through reactive oxygen species (ROS) measurements using flow cytometry analysis dicholoro-dihydro-fluorescen dia-acetate (DCF) assay. These results conveyed that nanohybrid adapts an oxidative stress mechanism upon cellular interaction where it utilizes the scavenging property of CeO 2, which induces the cell proliferation. Overall, the nano- CeO 2/RGO nanohybrid exhibits a prolonged biocompatibility and cell viability, which is highly desired for biomedical applications.