การสังเคราะห์อนุภาคทองนาโนด้วยวิธีการทางชีวภาพโดยใช้ เชื้อรา Aspergillus niger

• Main Author: ฉัตรวรเชษฐ์ แซ่โกว
• Other Authors: สริสา ณ ป้อมเพ็ชร์
• Format: Senior Project
• Language: Thai
• Published: จุฬาลงกรณ์มหาวิทยาลัย 2019
• Subjects: อนุภาคนาโน; ทอง; Nanoparticles; Gold
• Online Access: https://digiverse.chula.ac.th/Info/item/dc:10555
• Institution: Chulalongkorn University

Gold nanoparticles (AuNPs) are gold particles that range in size from 1-100 nm. Currently, biosynthesis of gold nanoparticle has gained increasing interest due to its environmental friendliness and less toxicity. In this method, enzymes and metabolites from organisms such as bacteria, fungi, yeasts, algaes and plants play an important role in the nanoparticle production. In this study, we aimed to biosynthesize AuNPs from Aspergillus niger MSCU 0361 and study the effects of different pH conditions on the synthesis of nanoparticles (pH 7 : water , pH 4.6 : acetate buffer). The absorbance result showed unique optical characteristics of AuNPs between 530-560 nm. The transmission electron microscopy (TEM) displayed the difference in shapes of synthesized AuNPs in water and acetate buffer. Most of AuNPs in acetate buffer were in spherical shapes, while the synthesized particles in water solution were found in spherical, triangular and uncertain shapes. Hydrodynamic diameters and size distributions of AuNPs were observed by dynamic light scattering (DLS) technique. The average size measured by DLS were 63.13 nm in acetate buffer and 90.01 nm in water solution. The catalytic activity of synthesized AuNPs was tested using resazurin reduction method, and found that the synthesized AuNPs tended to be able to catalyze resazurin giving resorufin products that could be measured by UV-visible spectrometry at the absorbance of 570 nm. These all results suggested that A. niger MSCU 0361 could synthesize nanoparticles, and the synthesized AuNPs in acetate buffer and in water solution were different. Moreover, the biosynthesized AuNPs could be used as catalyst for resazurin reduction. However, in order to confirm the ability of being an effective catalyst and to understand the catalytic mechanism of AuNPs, further studies are needed.