The UV-VIS Spectrum Analysis From Silver Nanoparticles Synthesized Using Diospyros maritima Blume. Leaves Extract

Research on the biological synthesis of silver nanoparticles (AgNPs) using plant extracts as reducing agents is growing rapidly because they are eco-friendly and cost-effective. Diospyros maritima Blume. is one of the plant species that had potential in the biosynthesis of AgNPs. In this study, biosynthesis of AgNPs was carried out by varying volume ratio of the extract and AgNO3 (5.0: 1; 2.0: 1; 0.5: 1; 0.2: 1; 0.1: 1) in reaction time (25 minutes, 2, 3, 24, 48, and 96 hours). The phytochemical screening results showed leaves extract of D. maritima contained phenols, flavonoids, saponins, and alkaloids, which may act as a reducing agent of Ag to Ag0. The biosynthetic solution's color was changed from brown to dark brown or black with the increasing reaction time. The UV-Vis spectra confirmed the formation of silver nanoparticles. The UV-Vis spectrum results showed the highest absorption peaks at 400 nm in solutions with a volume ratio of 0.5 :1, which showed the localized surface plasmon resonance (LSPR) characteristics of silver nanoparticles. From the UV-Vis spectrum can be analized that there are more than one peak of absorption at 350–500 nm in solutions with a volume ratio of 2.0:1. We carried out deconvolution of UV-Vis spectrum to separate each absorption peak. The formation of more than one absorption peak in the UV-Vis spectrum indicates a certain shape and silver nanoparticles size.