No abstract

Synthesis of gold nanoparticles (AuNPs) by reduction of HAuCl4 with p-aminobenzoic acid and p-aminosalicylic acid as a reducing agent was investigated. This work was conducted in order to determine the optimum condition of AuNPs synthesis and examine the effect of the hydroxyl group in p-aminosalicylic acid towards the size, shape, and stability of the synthesized gold nanoparticles (AuNPs). The optimum condition of the gold nanoparticles synthesis was determined by UV/Vis spectrophotometer, the shape and size of gold nanoparticles were measured by Transmission Electron Microscope (TEM). The synthesis process was started by reacting HAuCl4 and the reducing agents in an aqueous solution at 86 ºC. The initial gold concentration, reducing agents concentration and pH were varied in order to obtain the optimum condition. In the optimum condition, the results showed that p-aminosalicylic acid containing both hydroxyl and amino groups performed higher reduction ability compared to p-aminobenzoic acid that only containing an amino group. Reducing agents which have a hydroxyl group (p-aminosalicylic acid) could produce AuNPs with a smaller concentration of HAuCl4 than p-aminobenzoic acid. Gold nanoparticles that were synthesized with p-aminosalicylic acid were more stable and had a smaller particle size compared to its counterpart that is synthesized with p-aminobenzoic acid.

In this work, we determined the influence of reaction time in the synthesis of gold nanoparticles (AuNPs) by p-aminosalicylic acid and p-aminobenzoic acid as reducing agents. Besides working as a reducing agent, the p-aminobenzoic acid and paminosalicylic acid also simultaneously played a role as a capping agent/stabilizing agent. Gold ions were first mixed with the pH adjusted p-aminobenzoic acid and paminosalicylic acid. The mixture was then heated in boiling water at 86 °C. The formation of AuNPs was indicated by the appearance of red color and analyzed with UV/Vis spectrophotometry to evaluate their surface plasmon resonance (SPR) absorption in the wavelength range of 400-800 nm. The reducing ability of the reducing agents was affected by its structure. Gold nanoparticles that were synthesized with p-aminosalicylic acid were more stable, formed faster and had a smaller size than its counterpart that were synthesized with p-aminobenzoic acid. The stability test over a period of 5 months showed that the AuNPs were relatively stable.

Penanganan COVID 19, total kasus positif di Indonesia sebanyak  3.774.155 kasus, dari angka tersebut 3.247.715 orang dinyatakan sembuh, dan meninggal dunia 113.664 orang. Daya tahan tubuh yang rendah menjadi salah satu penyebab tingginya laju penularan covid-19. Kuatnya imunitas tubuh merupakan salah satu cara untuk menghindari infeksi virus COVID 19¬_Delta. Peningkatan antibody terhadap pathogen dapat dibentuk dengan mengkonsumsi dari jamu yang terbaut dari tanaman empon empon. Jamu herbal merupakan salah satu pilihan sebagai pengobatan alami untuk memperkuat imun tubuh masyarakat karena bahan baku yang mudah didapat, dan bisa dibuat sendiri. Tujuan  kegiatan pengabdian masyarakat ini di harapkan dapat meningkatkan keterampilan masyarakat dengan membuat jamu instan untuk meningkatkan imun tubuh secara mandiri. Metode plaksanaan, kegiatan dilaksanakan di Desa Torongrejo, Kecamatan Junrejo, Kota Batu. Metode pengambilan sampling data menggunakan metode Participation Action Research (PAR) dan analisis data memakai likert. Parameter yang diambil adalah persepsi masyarakat mengenai obat tradisional, Respon i masyarakat dalam budidaya tanaman rempah dan pemanfaatannya. Hasil kegiatan menunjukkan masyarakat respon terhadap pembuatan jamu instan, masyarakat menjadi  terampil  dalam mengolah rempah rempah disekitar rumah sebagai obat herbal alami. Masyarakat mengetahui tentang manfaat dan pentingnya pelestarian tanaman obat.