A review on titanium oxide nanoparticles modified metal-organic frameworks for effective CO2 conversion and efficient wastewater remediation.

Environmental pollution has been increasing since last decade due to increasing industrialisation and urbanisation. Various kinds ofenvironmental pollutants including carbon dioxide (CO2), dyes, pharmaceuticals, phenols, heavy metals along with many organic and inorganic species have been discovered in the various environmental compartments which possess harmful impacts tox human health, wildlife, and ecosystems. Thus, various efforts have been made through regulations, technological advancements, and public awareness campaigns to reduce the impact of the pollution. However, finding suitable alternatives to mitigate their impacts remained a challenge. Metal-organic frameworks (MOFs) are one of the advanced materials with unique features such as high porosity and stability which exhibit versatile applications in environmental remediation. Their composites with titanium oxide nanoparticles (TiO2) have been discovered to offer potential feature such as light harvesting capacity and catalytic activity. The composite integration and properties have been confirmed through characterization using surface area analysis, scanning electron/transmission electron microscopy, atomic force microscopy, fourier transformed infrared spectroscopy, X-ray diffraction analysis, X-ray photoelectron spectroscopy, thermogravimetric analysis, and others. Thus, this work rigorously discussed potential applications of the MOF@TiO2 nanomaterials for the CO2 capture and effective utilization in methanol, ethanol, acetone, acetaldehyde, and other useful products that served as fuel to various industrial processes. Additionally, the work highlights the effective performance of the materials towards photocatalytic degradation of both organic and inorganic pollutants with indepth mechanistic insights. The article will offer significant contribution for the development of sustainable and efficient technologies for the environmental monitoring and pollution mitigation.

Recent advances in waste-derived carbon dots and their nanocomposites for environmental remediation and biological applications.

The surging demand for eco-friendly nanomaterial synthesis has spurred the emergence of green approaches for synthesizing carbon dots (CDs). These methods utilized natural carbon sources, such as different kind of waste for CDs synthesis, underscoring their significance in waste management and circular economy initiatives. Furthermore, the properties of CDs can be tailored by their functionalization with different materials, enabling their versatile utilization in diverse scientific domains. In this regard, the current study delves into an in-depth review of recent advances in the green/sustainable fabrication of carbon dots nanocomposites (CDNCs) with metal/metal oxides and polymers within the timeframe of 2019-2023. It begins by categorizing different types of CDs, analyzing their associated nanocomposites with mechanistic insights. The primary focus is on green synthesis methods, particularly those that employ waste materials. Furthermore, we also discussed the applications of these CDs in both environmental and biological fields by covering areas such as catalysis, photocatalysis, heavy metal ion sensing, antimicrobial, and bioimaging with in-depth underlying mechanisms. At last, the review highlights the significant challenges with future directions. These include the pursuit of cost-effective green precursors, the advancement of streamlined one-step synthesis techniques, and their efficient utilization for diverse applications. Therefore, this review provides valuable insights for researchers seeking to enhance the functionality and sustainability of CDNCs by highlighting their potential to address environmental and biological challenges.

Biowaste to bioenergy nexus: Fostering sustainability and circular economy.

Existing fossil-based commercial products present a significant threat to the depletion of global natural resources and the conservation of the natural environment. Also, the ongoing generation of waste is giving rise to challenges in waste management. Conventional practices for the management of waste, for instance, incineration and landfilling, emit gases that contribute to global warming. Additionally, the need for energy is escalating rapidly due to the growing populace and industrialization. To address this escalating desire in a sustainable manner, access to clean and renewable sources of energy is imperative for long-term development of mankind. These interrelated challenges can be effectively tackled through the scientific application of biowaste-to-bioenergy technologies. The current article states an overview of the strategies and current status of these technologies, including anaerobic digestion, transesterification, photobiological hydrogen production, and alcoholic fermentation which are utilized to convert diverse biowastes such as agricultural and forest residues, animal waste, and municipal waste into bioenergy forms like bioelectricity, biodiesel, bio alcohol, and biogas. The successful implementation of these technologies requires the collaborative efforts of government, stakeholders, researchers, and scientists to enhance their practicability and widespread adoption.

Light-absorption-driven photocatalysis and antimicrobial potential of PVP-capped zinc oxide nanoparticles.

Toxic dyes in water bodies and bacterial pathogens pose serious global challenges to human health and the environment. Zinc oxide nanoparticles (ZnO NPs) demonstrate remarkable photocatalytic and antibacterial potency against reactive dyes and bacterial strains. In this work, PVP-ZnO NPs have been prepared via the co-precipitation method using polyvinylpyrrolidone (PVP) as a surfactant. The NPs' microstructure and morphology were studied using X-ray diffraction (XRD), having a size of 22.13 nm. High-resolution transmission electron microscope (HR-TEM) and field emission scanning electron microscopy (FESEM) analysis showed spherical-shaped PVP-ZnO NPs with sizer ranging from 20 to 30 nm. Fourier Transform Infrared Spectroscopy (FT-IR) confirmed the hybrid nature of the NPs, and UV-Vis spectroscopy showed an absorption peak at 367 nm. The PVP-ZnO NPs exhibited high photocatalytic activity, achieving 88% and nearly 95% degradation of reactive red-141 azo dye with 10 mg and 20 mg catalyst dosages, respectively. The antibacterial properties of the NPs were demonstrated against Escherichia coli and Bacillus subtilis, with inhibition zones of 24 mm and 20 mm, respectively. These findings suggest that PVP-ZnO NPs can be effectively used for water treatment, targeting both dye and pathogenic contaminants.

Facile synthesis of carbon quantum dot/silver nanocomposite and its antimicrobial, catalytic and sensing applications.

Environmentally benign synthesis of nanocomposite, a pivotal facet of nanotechnology, and gaining prominence due to the increasing demand for facile, sustainable, and safe synthesis methods. The present research reports an facile/cost-effective method for the preparation of carbon dots (CDs) and carbon dot silver nanocomposites ( CD@AgNCs) via a hydrothermal treatment of peanut shells. The well-dispersed and spherical CDs with an average diameter of 5-6 nm were obtained and further employed for the preparation of CD@AgNCs. The formation of CD@AgNCs. was confirmed by optical and microscopic studies and ared shift in the λmax from 277 nm (CDs) to 450 nm (CD@AgNCs) with a size range of 30-40 nm was observed. The synthesized CD@AgNCs exhibit excellent catalytic potency for the reduction of 4-nitrophenol to 4-aminophenol, and also displaying a unique interaction and sensing ability towards heavy metal ions (Hg2+), causing a pronounced change in color from reddish-brown to transparent with limit of detection (LOD) of 23.47 ppm. Also, the prepared composite exhibit efficient antimicrobial potential against gram-negative (Escherichia coli) bacteria. Consequently, this study delves into a unified effective remediation platform with the integration of catalysis, sensing, and antimicrobial potentials.

Biogenic silver based nanostructures: Synthesis, mechanistic approach and biological applications.

The alarming impact of antibiotic resistance sparked the quest for complementary treatments to overcome the confrontation over resistant pathogens. Metallic nanoparticles, especially silver nanoparticles (Ag NPs) have gained a much attention because of their remarkable biological characteristics. Moreover, their medicinal properties can be enhanced by preparing the composites with other materials. This article delves a comprehensive review of biosynthesis route for Ag NPs and their nanocomposites (NCs) with in-depth mechanism, methods and favorable experimental parameters. Comprehensive biological features Ag NPs such as antibacterial, antiviral, antifungal have been examined, with a focus on their potential uses in biomedicine and diagnostics has also been discussed. Additionally, we have also explored the hitches and potential outcomes of biosynthesis of Ag NPs in biomedical filed.

Potential medicinal plants to combat viral infections: A way forward to environmental biotechnology.

The viral diseases encouraged scientific community to evaluate the natural antiviral bioactive components rather than protease inhibitors, harmful organic molecules or nucleic acid analogues. For this purpose, medicinal plants have been gaining tremendous importance in the field of attenuating the various kinds of infectious and non-infectious diseases. Most of the commonly used medicines contains the bioactive components/phytoconstituents that are generally extracted from medicinal plants. Moreover, the medicinal plants offer many advantages for the recovery applications of infectious disease especially in viral infections including HIV-1, HIV-2, Enterovirus, Japanese Encephalitis Virus, Hepatitis B virus, Herpes Virus, Respiratory syncytial virus, Chandipura virus and Influenza A/H1N1. Considering the lack of acceptable drug candidates and the growing antimicrobial resistance to existing drug molecules for many emerging viral diseases, medicinal plants may offer best platform to develop sustainable/efficient/economic alternatives against viral infections. In this regard, for exploring and analyzing large volume of scientific data, bibliometric analysis was done using VOS Viewer shedding light on the emerging areas in the field of medicinal plants and their antiviral activity. This review covers most of the plant species that have some novel bioactive compound like gnidicin, gniditrin, rutin, apigenin, quercetin, kaempferol, curcumin, tannin and oleuropin which showed high efficacy to inhibit the several disease causing virus and their mechanism of action in HIV, Covid-19, HBV and RSV were discussed. Moreover, it also delves the in-depth mechanism of medicinal with challenges and future prospective. Therefore, this work delves the key role of environment in the biological field.

Recent advances in nanomaterials based sustainable approaches for mitigation of emerging organic pollutants.

Emerging organic pollutants (EOPs) are a category of pollutants that are relatively new to the environment and recently garnered a lot of attention. The majority of EOPs includes endocrine-disrupting chemicals (EDCs), antibiotic resistance genes (ARGs), pesticides, dyes and pharmaceutical and personal care products (PPCPs). Exposure to contaminated water has been linked to an increase in incidences of malnutrition, intrauterine growth retardation, respiratory illnesses, liver malfunctions, eye and skin diseases, and fatalities. Consequently, there is a critical need for wastewater remediation technologies which are effective, reliable, and economical. Conventional wastewater treatment methods have several shortcomings that can be addressed with the help of nanotechnology. Unique characteristics of nanomaterials (NMs) make them intriguing and efficient alternative in wastewater treatment strategies. This review emphasis on the occurrence of divers emerging organic pollutants (EOPs) in water and their effective elimination via different NMs based methods with in-depth mechanisms. Furthermore, it also delves the toxicity assessment of NMs and critical challenges, which are crucial steps for practical implementations.

Racemization rate and biomolecular characterization of D-serine synthesizing bacteria Bacillus tequilensis A1C1.

D-amino acids, the important components of the bacterial cell walls, are valuable molecular and genetic markers of bacterial-derived organic material in the environment. D-serine, a racemization product of L-serine is one such amino acid present in various prokaryotes and eukaryotes. It is a well-recognized regulator of various activities in the human nervous system. In plants, it has a role in the nitrogen cycle regulation and pollen tube growth. Serine enantiomers are present in different concentrations and few bacterial strains are reported to contribute to D-serine in the environment. During the present study, soil samples from different places in North India were collected and processed to isolate and screen the bacteria on M9 minimal media (Himedia) for D-serine synthesis. Thin-layer chromatography (TLC Silica gel 60 F 254 (20 × 20 cm, Merck, Darmstadt, Germany) and Mass spectroscopic analysis (Bruker MICROTOF II spectrometer) studies, etc were performed. D-serine-producing isolates were characterized as per standard procedures. Bacterial isolate A1C1 with maximum D-serine (0.919 ± 0.02 nM) synthesis under optimal growth conditions (37°C ± 0.5, 150 ± 0.5 RPM, and 7 ± 0.5 pH) was identified as Bacillus tequilensis based on 16sRNA sequencing. The isolate could be a valuable serine racemization tool for various industrial and environmental applications.

Tuning of (E)-(4-fluorophenyl)-1,1-diamino-2,3-diazabuta-1,3-diene nanostructures for the selective detection of imidacloprid.

The present work demonstrates a facile route for synthesizing the organic nanoparticles (ONPs) and the blue fluorescent Quantum Dots (QDs) based on an organic molecule named (E)-(4-fluorophenyl)-1,1-diamino-2,3-diazabuta-1,3-diene. The synthesis process possesses advantages viz green synthesis, non-toxic degraded products, and amount of organic compound. Initially, the ONPs were prepared using the nanoprecipitation method and were screened for their recognition potential against various pesticides, however, no selectivity has been observed. This motivated us to tune the ONPs into QDs. The QDs were prepared using the hydrothermal method and a color change was observed in the QDs solution under daylight and under a UV lamp. The emission wavelength was observed at 400 nm (λexcitation = 278 nm). The synthesized QDs exhibited selective sensing potential towards imidacloprid via a quenching mechanism. A normalised decrement in the luminescence intensity of QDs was observed on raising the concentration of imidacloprid and a good linear response was noticed over a concentration varies from 1 µM to 100 µM with a regression coefficient of 0.99. The detection limit was estimated to be 4.53 nM and quantification limit was calculated to be and 13.72 nM.

Chromatographic techniques for the analysis of organophosphate pesticides with their extraction approach: a review (2015-2020).

In agriculture, a wide range of OPPs has been employed to boost crop yield, quality, and storage life. However, due to the ever-increasing population and rapid urbanization, pesticide use has surged in recent years. These compounds are exceedingly poisonous to humans, and despite the fact that specific legislation prohibits their use, the frequency of toxic and/or fatal incidents, as well as current statistics, suggest that they are currently accessible. As a result, determining the exposure to these substances as well as their detection (and that of their metabolites) in different types of exposed samples has become a hot issue in terms of quality and safety concerns. However, developing tools for the evaluation of these substances is a critical challenge for laboratories. Various chromatographic-based methods reported in the period of 2015-2020 have been developed, which are summarized and critically reviewed in this article, including the extraction of the target OPPs from different kinds of matrices. A comparison among the extraction and analysis techniques has been made in the current review article.

Recent advancements in the detection of organophosphate pesticides: a review.

Organophosphorus pesticides (OPPs) are generally utilized for the protection of crops from pests. Because the use of OPPs in various agricultural operations has expanded dramatically, precise monitoring of their concentration levels has become the critical issue, which will help in the protection of ecological systems and food supply. However, the World Health Organization (WHO) has classified them as extremely dangerous chemical compounds. Taking their immense use and toxicity into consideration, the development of easy, rapid and highly sensitive techniques is necessary. Despite the fact that there are numerous conventional ways for detecting OPPs, the development of portable sensors is required to make routine analysis considerably more convenient. Some of these advanced techniques include colorimetric sensors, fluorescence sensors, molecular imprinted polymer-based sensors, and surface plasmon resonance-based sensors. This review article specifically focuses on the colorimetric, fluorescence and electrochemical sensors. In this article, the sensing strategies of these developed sensors, analytical conditions and their respective limit of detection are compiled.