Heavy metals are pollutants that are harmful to living things and the environment can be degraded by microbes or understood by other living things so that they can cause health problems. One of the heavy metals that is often found in wastewater is lead. Lead is widely used in the manufacture of batteries, metal products such as ammunition, cable coatings, Polyvinyl Chloride (PVC) tubing, solder, chemicals and dyes This use causes humans to be exposed to large amounts of lead. One method to deal with lead pollution is to use photocatalysts. Photocatalysts react with heavy metals and reduce them so that the level of toxicity becomes lower than before through photocatalytic reactions. In this study, synthesis of reduced graphene oxide/silver nanoparticle nanoparticles was performed by facile hydrothermal methods for photocatalytic degradation of Pb ion. The characterization results indicate that the synthesis has been successfully carried out. The successful result of rGO/AgNPs nanocomposites synthesis was proved by several techniques such as X-ray diffraction analysis, Raman, UV-Vis spectroscopy, Scanning Electron Microscopy (SEM) and Energy Dispersive X-Ray analysis (EDX). This indicates the presence of these groups in the graphene oxide and rGO/AgNPs samples, respectively. The resulting rGO/AgNPs nanocomposite has an absorbance peak at a wavelength of 267 nm. The diffraction peaks for nanocomposites rGO/AgNPs and their Miller indices were 38.08° (111), 44.16° (200), 64.44° (220), and 77.44° (311). The Raman spectra of rGO/AgNPs exhibits D bands at 1334,13 with intensity of 630,60 cm−1 and G band at 1594,61 with intensity of 477,29 cm−1. The ID/IG ratio rGO/AgNPs-NaBH4 is ~1,32. Furthermore, the photocatalytic activity test results showed that the rGO/AgNPs nanocomposite was able to reduce Pb2+ to Pb with a maximum exposure time of 1.5 hours

<p>Meluasnya penyebaran <em>Methicillin Resistant Staphylococcus aureus</em> (MRSA) yang kebal terhadap antibiotik β-laktam membuat penelitian untuk menemukan senyawa aktif yang memiliki potensi sebagai antibakteri MRSA menjadi penting. Salah satu penelitian yang dapat dilakukan adalah studi penambatan molekul. Studi penambatan molekul telah dilakukan menggunakan senyawa bahan alam dari minyak kayu manis dan minyak serai dapur dengan reseptor enzim <em>Penicillin Binding Protein</em> 2a (PBP2a). Studi ini memiliki tujuan untuk memprediksi kemampuan senyawa bahan alam dari kedua minyak atsiri tersebut sebagai antibakteri MRSA. Penambatan molekul dilakukan menggunakan perangkat lunak (<em>software</em>) AutoDock 4.2. Hasil penelitian menunjukkan bahwa senyawa dengan potensi sebagai antibakteri paling besar adalah trans-β-kariofilen dan geranil asetat dengan energi ikat sebesar -6,12 dan -5,11 kkal/mol dan konstanta inhibisi sebesar 32,69 dan 180,41 µM. Hasil penambatan molekul kemudian dilanjutkan dengan simulasi dinamika molekular. Hasil simulasi dinamika molekular menunjukkan bahwa kedua senyawa memiliki nilai <em>Root Mean Square Deviation</em> (RMSD) yang tinggi.</p><strong>Molecular Docking and Molecular Dynamics Simulation of Cinnamon Oil and Kitchen Lemongrass Oil as Antibacterial Agent Against <em>Methicillin-Resistant</em> <em>Staphylococcus aureus</em>. </strong>The spread of <em>Methicillin-Resistant</em> <em>Staphylococcus aureus</em> (MRSA) caused the research for its antibiotic to become more pressing than ever. One of the research that can be conducted is a molecular docking study. A molecular docking study of natural products from cinnamon and lemongrass oil with Penicillin Binding Protein 2a (PBP2a) enzyme was conducted. This study aims to predict the ability of each natural product to become an MRSA antibiotic. The molecular docking was conducted with AutoDock 4.2 software. The result shows that β-caryophyllene and geranyl acetate have the most potential to become MRSA antibiotics with binding energies of -6.12 kcal/mol and -5.11 kcal/mol and inhibition constants of 32.69 μM and 180.41 µM, respectively. The results of molecular docking were validated using molecular dynamic simulation. Molecular dynamic simulation shows that both complexes have a high root mean square deviation (RMSD) value.