Cutting-edge technologies are making inroads into new areas and this remarkable progress has been successfully influenced by the tiny level engineering of carbon dots technology, their synthesis advancement and impressive applications in the field of allied sciences. The advances of science and its conjugation with interdisciplinary fields emerged in carbon dots making, their controlled characterization and applications into faster, cheaper as well as more reliable products in various scientific domains. Thus, a new era in nanotechnology has developed into carbon dots technology. The understanding of the generation process, control on making processes and selected applications of carbon dots such as energy storage, environmental monitoring, catalysis, contaminates detections and complex environmental forensics, drug delivery, drug targeting and other biomedical applications, etc., are among the most promising applications of carbon dots and thus it is a prominent area of research today. In this regard, various types of carbon dot nanomaterials such as oxides, their composites and conjugations, etc., have been garnering significant attention due to their remarkable potential in this prominent area of energy, the environment and technology. Thus, the present paper highlights the role and importance of carbon dots, recent advancements in their synthesis methods, properties and emerging applications.

Nanomaterials have gained huge applications ever since their discoveries, especially in the field of electronics, medicine, research, and environmental cleanup. Nanomaterials have a high surface area-to-volume ratio along with high surface energies making them suitable for such wide applications. Carbon nanotubes (CNTs) and carbon nanocomposite (CNC) materials are remarkable nanomaterials that have become the backbone of most industries these days. Both materials have gained huge attention in the last decade by the scientific community. CNTs come in two variants, i.e., single-walled CNTs (SW-CNTS) and multiwalled CNTs (MW-CNTs). Due to their wider applications, CNT synthesis is currently emerging with the advancement in technology. Currently, CNTs are being synthesized by chemical as well as physical approaches. The current review article focuses on the vital research and application for the synthesis of CNTs depending on the quality of the nanotube materials. Controlled routes to their organization and assembly are also discussed in detail over here. The aim is to provide recent advances in the synthesis methods, of CNTs, their current applications, future applications, and the potential of agrowaste and industrial waste for the synthesis of CNTs and nanomaterials.

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Objective: An attempt has been made to study phytoconstituents and High-Performance Thin Layer Chromatography (HPTLC) fingerprinting pattern of leaf/stem/root methanol extracts of Avicennia marina. Methods:The phytochemical screening was done by standard biochemical methods and standard optimized HPTLC densitometry determination was performed under two different energy zones [under UV-254 nm and under 540 nm after derivatization at sample size-10 µl, temperature = 25.8±0.3 °C (constant) and relative humidity = 86±1% (constant) in optimized solvent system].Results: Phytochemical analysis confirmed the presence of phytochemicals in the leaf, stem, and root of the plant. Under UV-254 nm energy range, the leaf, stem and root extract showed the presence of 8, 6 and 5 components respectively and under 540 nm energy zone after derivatization, the leaf, stem and root extract revealed the presence of 7, 5 and 5 components, respectively and specific marker components with very high concentration (under UV-254 nm; 3, 2, 2 in leaf, stem, and root respectively and under 540 nm after ASR treatment; 2, 1, 2 in leaf, stem, and root respectively) were detected among them. Conclusion:The preliminary phytochemical test results elucidated Avicennia marina leaf, stem, and root as a hug reservoir of various class of phytochemicals and metabolites. The results obtained by HPTLC fingerprinting method found to be acceptable as a quick, reliable, accurate and economical for identification and authentication of Avicennia marina mangrove plant and useful to differentiate this mangrove species from other similar mangroves, in a single TLC plate run. This serves as a biochemical marker pattern for leaf, stem and root parts of this mangrove and for its diverse phytoconstituents.

Environmental pollution is becoming more prevalent in both human life and the ecosystem. The increased use of fossil fuels, mining, and the burning of wastes, as well as industrial wastewater discharge, are polluting natural resources such as water, soil, and air. Metals (loid)s (Cu, Cr, Cd, Zn, Ni, Pb, Hg, Sb, Sn, and As) contribute to several ecological problems when exposed to humans and the environment resulting in serious health and environmental risks. The pollution of aquatic and terrestrial sites with these elements is an issue of environmental as well as public health significance. The present review highlights environmental problems instigated by the toxic metal (loid)s, their source, and respective health/environmental concern along with the importance of creating low-cost, environmentally acceptable clean-up technologies for treating household and industrial wastewater. Various physical, chemical, biological, and/or biochemical as well as their various combinations have been described from the sustainable technological point of view. Techniques such as ion exchange, membrane filtration, photocatalysis, bioremediation, phytoremediation, economical biosorbents, and nanomaterials have been discussed in detail along with respective recent case studies to gain a significant inside towards the solution of the environmental problems focused and action-oriented sustainable technologies development. Thus, this article significantly provides a deep insight into metal (loid)s toxicity, source identification, and their influences on the ecosystem and human health along with conventional and sustainable clean-up technologies.