*2.3. In-Situ Biofabrication of Treated C. pentandra Fiber with Ag-NPs*

This in-situ process was done using two steps of the loading process by following the method of Ravindra et al. [11] and Sivaranjana et al. [13] with some modification as shown in Figure 2b. Firstly, the treated *C. pentandra* fiber was immersed in the *E. spiralis* extract. The treated *C. pentandra* fiber was immersed in the 30 mL of *E. spiralis* extract (2.5 g) in a 150 mL conical flask. The *E. spiralis* extract was prepared based on the previous study [14]. The mixture was then shaken at ~52 ◦C using water bath shaker at 130 strokes/min for 48 h. Then, the fiber was filtered using filter paper and kept for the next step. Secondly, the immersed treated *C. pentandra* fiber in *E. spiralis* extract was then immersed in 3 mL of 0.1 M AgNO3 solution as a silver precursor. The mixture was shaken in a water bath shaker at 130 stroke/min and temperature of ~52 ◦C for 48 h. After the shaking process, the fiber was filtered from the solution and washed with deionized for two times to remove any excess of AgNO3 solution before being dried in an oven at 60 ◦C overnight. The treated *C. pentandra* fiber loaded with Ag-NPs was abbreviated as *C. pentandra*/Ag-NPs hereafter.

As a control, the treated *C. pentandra* fiber was immersed only in AgNO3 solution in the absence of *E. spiralis* extract to determine the significant of *E. spiralis* extract. A mass of 1.0 g of treated *C. pentandra* fiber was immersed into the 30 mL of 0.1 M AgNO3 in different conical flasks. The mixture of fiber was shaken in a waterbath shaker (Memmert, Germany) at 130 stroke/min and temperature of 52 ◦C for 48 h. The fiber was then filtered and washed with 100 mL of deionized water two times to remove any excess of AgNO3 solution before dried in the oven overnight at 60 ◦C. The treated *C. pentandra* fiber immersed only in the AgNO3 solution was then stored in the plastic container for further usage and abbreviated as *C. pentandra*/Ag-NO3 hereafter.
