Preparation and characterization of stable Core/Shell Fe3O4@Au ‎decorated with amine group for immobilization of lipase by covalent ‎attachment

The self-assembly approach was used for amine decoration of core/shell Fe3O4@Au with 4-aminothiphenol. This structure was used for covalent immobilization of lipase using a Ugi 4-component reaction. The amine group on the structure and carboxylic group from lipase can react in the Ugi reaction and a firm and stable covalent bond creates between enzyme and support. The synthesized structure was fully characterized and its activity was explored in different situations. The results displayed the pH and temperature stability of immobilized lipase compared to free lipase in a wide range of pH and temperature. Also after 60 days, it showed excellent activity while residual activity for the free enzyme was only 10%. The synthesized structure was conveniently separated using an external magnetic field and reused 6 times without losing the activity of the immobilized enzyme.

Application Education as a Place to Increase Community Income During the Covid-19 Pandemic in Parungponteng

Blood clams (Anadara granosa) are endemic clams found in Southeast Asia and East Asia. Blood clams are widely consumed by the public as seafood dishes in coastal food stalls. The great potential of blood clams will increase the waste of clam shells produced. The accumulation of shellfish waste will cause pollution and reduce environmental aesthetics. The chitin content in blood clam shells can be used as chitosan. Chitosan is a polymer of -(1-4) glucosamine which is formed when the acetyl group in chitin is substituted by hydrogen to become an amine group. Chitosan has antibacterial and antifungal properties. Isolation of chitosan was carried out through the stages of demineralization, deproteination, and deacetylation. The limited use of laboratories during the pandemic is a major obstacle in the isolation process of chitosan. This study aims to process blood clam shell waste into chitosan in a simple way on a home scale. Processing includes deproteination, demineralization, and deacetylation were done using tools and materials available at home. Laboratory equipment such as beakers could be replaced with pots, the reflux process was replaced by using a cloth to filter, and measuring cups were replaced with glasses. The research used 1500 grams of blood clam shell powder and produced 1050 grams of white chitosan with a slightly hard texture.

Antimicrobial Study of Green Synthesized Silver Nanoparticles (AgNPs) by Using Ageratina adenophora and its Characterization

Green chemistry refers to the design of chemical product and processes that reduce or eliminate the generation of hazardous substances. Silver nanoparticles (AgNPs) were synthesized successfully from AgNO3 through a simple green synthetic route using Ageratina adenophora leaf extract which acts as both reducing and capping agents. As synthesized AgNPs were characterized with the help of X-ray diffraction (XRD) and Fourier transform infrared (FTIR) spectroscopy. XRD study shows crystalline nature of silver nanoparticles and average particle size was calculated as 24 nm using Debye Scherrer equation. Functional group responsible for the reduction of silver ion was investigated using FTIR spectroscopy. Hydroxyl group, amine group, aliphatic amine group were detected from FTIR analysis. Further, the green synthesized nanoparticles were found to be highly toxic against bacteria: Bacillus subtilis and Escherichia coli showing zone of inhibition of 11 mm and 9 mm, respectively. Int. J. Appl. Sci. Biotechnol. Vol 9(2): 128-132.

One-Pot Synthesis of Nano CuO-ZnO Modified Hydrochar Derived from Chitosan and Starch for the H2S Conversion

A novel kind of hydrochar adsorbent, modified by CuO-ZnO and derived from chitosan or starch, was synthesized for H2S adsorption. The prepared adsorbent was characterized by BET, XRD, EDX, SEM, and XPS. The results showed that the modified hydrochar contained many amino groups as functional groups, and the nanometer metal oxide particles had good dispersion on the surface of the hydrochar. The maximum sulfur capacity reached 28.06 mg/g-adsorbent under the optimized conditions. The amine group significantly reduced the activation energy between H2S and CuO-ZnO conducive to the rapid diffusion of H2S among the lattices. Simultaneously, cationic polyacrylamide as a steric stabilizer could change the formation process of CuO and ZnO nanoparticles, which made the particle size smaller, enabling them to react with H2S sufficiently easily. This modified hydrochar derived from both chitosan and starch could be a promising adsorbent for H2S removal.

CO2 Absorption Mechanism by Diamino Protic Ionic Liquids (DPILs) Containing Azolide Anions

Protic ionic liquids have been regarded as promising materials to capture CO2, because they can be easily synthesized with an attractive capacity. In this work, we studied the CO2 absorption mechanism by protic ionic liquids (ILs) composed of diamino protic cations and azolide anions. Results of 1H nuclear magnetic resonance (NMR), 13C NMR, 2-D NMR and fourier-transform infrared (FTIR) spectroscopy tests indicated that CO2 reacted with the cations rather than with the anions. The possible reaction pathway between CO2 and azolide-based protic ILs is proposed, in which CO2 reacts with the primary amine group generated from the deprotonation of the cation by the azolide anion.