Iron oxides are chemical compounds which have different polymorphic forms, including γ-Fe2O3 (maghemite), Fe3O4 (magnetite), and FeO (wustite). Among them, the most studied are γ-Fe2O3 and Fe3O4, as they possess extraordinary properties at the nanoscale (such as super paramagnetism, high specific surface area, biocompatible etc.), because at this size scale, the quantum effects affect matter behavior and optical, electrical and magnetic properties. Therefore, in the nanoscale, these materials become ideal for surface functionalization and modification in various applications such as separation techniques, magnetic sorting (cells and other biomolecules etc.), drug delivery, cancer hyperthermia, sensing etc., and also for increased surface area-to-volume ratio, which allows for excellent dispersibility in the solution form. The current methods used are partially and passively mixed reactants, and, thus, every reaction has a different proportion of all factors which causes further difficulties in reproducibility. Direct active and complete mixing and automated approaches could be solutions to this size- and shape-controlled synthesis, playing a key role in its exploitation for scientific or technological purposes. An ideal synthesis method should be able to allow reliable adjustment of parameters and control over the following: fluctuation in temperature; pH, stirring rate; particle distribution; size control; concentration; and control over nanoparticle shape and composition i.e., crystallinity, purity, and rapid screening. Iron oxide nanoparticle (IONP)-based available clinical applications are RNA/DNA extraction and detection of infectious bacteria and viruses. Such technologies are important at POC (point of care) diagnosis. IONPs can play a key role in these perspectives. Although there are various methods for synthesis of IONPs, one of the most crucial goals is to control size and properties with high reproducibility to accomplish successful applications. Using multiple characterization techniques to identify and confirm the oxide phase of iron can provide better characterization capability. It is very important to understand the in-depth IONP formation mechanism, enabling better control over parameters and overall reaction and, by extension, properties of IONPs. This work provides an in-depth overview of different properties, synthesis methods, and mechanisms of iron oxide nanoparticles (IONPs) formation, and the diverse range of their applications. Different characterization factors and strategies to confirm phase purity in the IONP synthesis field are reviewed. First, properties of IONPs and various synthesis routes with their merits and demerits are described. We also describe different synthesis strategies and formation mechanisms for IONPs such as for: wustite (FeO), hematite (α-Fe2O3), maghemite (ɤ-Fe2O3) and magnetite (Fe3O4). We also describe characterization of these nanoparticles and various applications in detail. In conclusion, we present a detailed overview on the properties, size-controlled synthesis, formation mechanisms and applications of IONPs.

This present study for the first time reports a facile and ecofriendly route for synthesis of Silver nanoparticles by using the extract of berries of Pimenta dioica. Extract of berries was used for reduction of silver nitrate into silver nanoparticles (AgNPs). Silver nanoparticles have unique phytochemical properties and activities compared to their whole parent material. Due to multiple applications of Silver nanoparticles (AgNPs) various biological methods are gaining recognition for their production. The silver nanoparticles were irregular spherical in shape. In the reaction mixture brown color appeared which confirmed the primary indication of Ag NPs formation and it was confirmed by using UV-visible spectroscopy which shows maximum peak intensity at 425 nm. Sample was characterized by using UV-viz Spectrophotometer, SEM, and TEM. The synthesized silver nanoparticles were spherical in clusters. Crystalline size calculated was found to be 40 nm; and TEM shows that synthesized nanoparticles having size of 94±29 nm. The Ag NPs were evaluated for their antimicrobial activity on Gram negative bacteria Escherichia coli and Gram positive Staphylococcus aureus bacteria by qualitative methods and it was confirmed.

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The synthesis of silver nanoparticles using plant extract as a capping agent has been very easy, economical and environment friendly method. The Madhuca longifolia is one of the well-known trees for its various benefits from food industry to its medicinal applications. It is indigenous to India, Nepal, Sri Lanka and Myanmar. In the present aqueous extract was used from leaves of M. lngifolia has been used as a capping agent to form AgNPs by reducingsilver nitrate with the help of green synthesis route. UV-visible spectroscopicy gave maximaat 420 nmconfirmed the synthesis of M. longifolia AgNPs. Characterization was done by TEM, SEM, XRD and FTIR techniques. FTIR confirmed the presence of various phytochemicals and formation of nanoparticles. XRD confirmed the formation of crystalline structure of synthesized silver nanoparticles. The shape of silver nanoparticles was irregular and spherical. The reaction solution turned brown which is the primary indication of formation of AgNPs. Crystalline size was calculated and found to be 10–25 nm; and TEM showed the size of nanoparticles around 5–40 nm. The M. longifolia based Silver nanoparticles were evaluated for their antibacterial and antibiofilm activity on Staphylococcus aureus (Gram positive) and Escherichia coli (Gram negative) by disc diffusion and percentage inhibition methods was confirmed.

Pectin is a polysaccharide present in fruit cell walls can be extracted from fruit wastes obtained after processing. The objective of the present investigation was to study the potential of citrus fruit peels to be a source of pectin as it is of great importance in food and medical industry. This study aimed at comparing the characteristics of different pectin and to see which one is more suitable for industrial application. Pectin was extracted using alcohol precipitation method from peels of grapefruit, mousambi, and orange so that the use of pectin can be applied to a wider range. According to the study, the pectin extracted by mousambi on wet basis (17.1%) was higher in comparison to the pectin extraction of orange and grapefruit. The pectin can be used in many fields like food and medicines so the improvement in quality and production is very important. MicroRNAs have the main function of guiding the base pairing with target mRNA to negatively regulate its expression for gene silencing via mRNA clevage. In the present study we also found the phylogenetic relationship among the citrus fruits by multiple sequence alignment of microRNAs stem-loop sequence from the miRbase database of the citrus fruits and after getting phylogenetic tree we got the common ancestors. In recent years, the center of production has moved to Europe and to citrus- producing countries like Mexico and Brazil. Further changes of structure and location of the industry continue, but are constrained by the need for large capital investment to setup Plant of economic size, and the need for a large-scale source or sources of raw material.