## 3 Results and Discussion
### Characteristics of NP Powder  
Figure 2A presents the powder XRD patterns of Au, Ag, and Au-Ag alloy NPs. The XRD patterns of all NPs exhibited four distinct diffraction peaks at 2\(\theta\) values of 38.2\({}^{\circ}\), 43.5\({}^{\circ}\), 65.1\({}^{\circ}\), and 77.9\({}^{\circ}\), corresponding to the characteristic diffractions of the (111), (200), (220), and (311) planes, respectively, in accordance with the face-centered cubic structure [35]. The Au-Ag alloy NPs had similarities with both Au and Ag NPs, attributable to their closely related lattice constants (Au: JCPDS 4-0783; Ag: JCPDS 4-0784).  
Figure 2B presents the TG curve for Au-Ag alloy NPs. The weight loss observed in these NPs could be categorized into four stages, with weight losses of 3.8%, 18.2%, 30.4%, and 24.7% occurring at temperatures of <100, 100-320, 320-750, and 750-900 \({}^{\circ}\)C, culminating in a total weight loss of 77.1%. At the first stage, weight loss likely resulted from the desorption of water molecules adsorbed on the NP surfaces. At the second stage, weight loss likely resulted from the thermal degradation of small molecules from plant residues loosely bound to the NPs. At the third stage, weight loss likely resulted from the desorption of bioactive molecules derived from MQLE, which played a crucial role in the reduction and capping processes during NP synthesis [28]. At the final stage, weight loss likely resulted from the decomposition of residual compounds. The  
Figure 2: (**A**) XRD patterns of Ag, Au, and Au-Ag alloy NPs. (**B**) TG curve of Au-Ag alloy NPs heated from 30 to 900 \({}^{\circ}\)C in a N\({}_{2}\) atmosphere.  
observed in stages 2-4 indicates the presence of a substantial amount of MQLE on the NP surfaces. Given that Au-Ag alloy NPs were in situ capped with bioactive compounds in MQLE--for example, polyphenols, flavonoids, and terpenoids [7], they exhibited a stable capping function that enhanced their applicability across industrial sectors.  
FE-SEM revealed no significant morphological differences among Au, Ag, and Au-Ag alloy NPs; the NPs predominantly exhibited elliptical and spherical shapes. The average diameters of Au, Ag, and Au-Ag alloy NPs were 42 \(\pm\) 2.6, 26 \(\pm\) 1.3, and 37 \(\pm\) 2.2 nm, respectively. The literature suggests that most NPs synthesized using green methods with _Jasminum sambac_, _Barleria prionitis_, _Plumbago zeylanica_, and citrus peel extracts predominantly exhibit spherical or elliptical geometries [28; 30; 32; 36]. However, only a limited number of NPs derived from _Glorosa superba_ and _Hubertia ambavilla_ extracts exhibit alternative shapes [3; 11]. In the present study, the average particle size of Au-Ag alloy NPs was slightly larger than that of NPs synthesized using chemical methods or those derived from _J. sambac_, _G. superba_, _Trapa_ peels, and _Tamarix aphylla_ extracts [3; 37; 28; 38; 39]; this difference may be attributable to the accelerated reduction process (60 s).  
EDS confirmed that Au constituted 86.61% of Au NPs, whereas Ag constituted 85.23% of Ag NPs (Table 1). Thus, Au and Ag were the predominant components in corresponding NPs. In Au-Ag alloy NPs, Au and Ag were present at proportions of 43.56% and 40.21%, respectively. Trace amounts of C and O were detected, likely because of the capping of the NPs by MQLE-derived phytochemicals. Furthermore, the distribution of Au and Ag was more uniform in Au-Ag alloy NPs synthesized using MQLE than in those synthesized using _J. sambac_ extract (50.74% Au vs. 29.99% Ag) or _G. superba_ extract (2.49% Au vs. 49.79% Ag) [3; 28]. This uniformity suggests that the Au-Ag alloy NPs synthesized in this study exhibit enhanced pharmacological activity.