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This work aimed at controlling the size of chitosan nanoparticles that were prepared by the ionotropic gelation method. Quantities of chitosan and sodium tripolyphosphate (STPP) were optimized to obtain a fine size and narrow size distribution of the nanoparticles. X-ray diffraction and selected area electron diffraction patterns indicated the existence of both crystalline and amorphous phases of chitosan. Particle size and size distribution were determined using transmission electron microscopy and dynamic laser scattering techniques. The size of the chitosan particles decreased with a reduction in STPP content due to a decrease in cross-link bonding and the formation of aggregate particles. Using this facile approach, the finest particles of chitosan were obtained in a range of 3-6 nm.

Phyllanthin is known to have therapeutic properties such as immunomodulator, nephroprotective, and anticancer. Phyllanthin is a lignan compound that is commonly found in plants of the Phyllanthus genus, one of which is green meniran (Phyllanthus niruri). Solvent Ionic Liquid (IL) is one of the alternative solvents that are widely used for the extraction of compounds from a plant. The purpose of this study were to compare the extraction yield of philanthine compounds from meniran herbs using IL solvent by Microwave Assisted Extraction (MAE) with methanol by maceration method, and to determine the IL solvent that could produce the highest phyllanthin content. Optimization were carried out using the independent variables IL solvent concentration (0.25 M, 0.75 M, and 1.25 M) and sample-solvent mixture (1:10, 1:12, and 1:14). The variable modeling is designed using Response Surface Methodology that produced 9 runs of combination of solvent concentration and sample-solvent mixture ratio. The phyllanthin assay was using High Performance Liquid Chromatography (HPLC) with ethanol-water mixture (66:34) as mobile phase and wavelength at 229 nm for detection. The optimum extraction conditions showed the best results for imidazolium chloride IL at 1st run with a concentration of 0.75 M, the sample-solvent mixture of 1:14 and phyllanthin content of 0.1783 mg/g while imidazolium bromide IL at 7th run with a concentration of 0.75 M and the sample-solvent mixture of 1:12 and phyllanthin content of 0.23 mg/g. However, the methanol maceration method could only extract phyllanthin as much as 0.1319 mg/g. Based on these results, the use of IL-MAE was more effective than the methanol maceration method due to higher phyllantin extract.

Gold nanoparticles (AuNPs) were found to act as antioxidants owing to their inert, high stability, biocompatibility, and non-cytotoxic. The present investigation involved the synthesis of gold nanoparticles through the electrodeposition technique on a substrate comprising Fluorine-doped Tin Oxide (FTO). By manipulating the scan rate parameter, an effective approach can be employed to facilitate precise management of particle morphology and size. The obtained shape of AuNPs were spherical and irregular. In this study, it was observed that gold nanoparticles elicited potent inhibition, particularly at a scan rate of 150 mV/s, with a markedly high inhibition value of 41.27%. The outcome was further supported by an augmented particle distribution density per unit area, which measured as 149,635,036.5/mm².

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