3.3.1. UV-vis Spectroscopy Analysis

The UV-vis spectra of untreated *C. pentandra* fiber, treated *C. pentandra* fiber, *C. pentandra*/Ag-NPs are shown in Figure 7. The Ag peak in UV-vis spectra appeared around 400 to 450 nm. However, no Ag peak was observed in the UV-vis spectra of untreated and treated *C. pentandra* fiber alone. The highest intensity of Ag peak of *C. pentandra*/Ag-NPs appeared around 400–450 nm confirmed the success of Ag-NPs produced in *C. pentandra* fiber in the presence of *E. spiralis* extract [31].

**Figure 7.** UV–vis spectra of untreated *C. pentandra* fiber, treated *C. pentandra* fiber and *C. pentandra*/ Ag-NPs.
