## 4 Conclusions  
In conclusion, our study demonstrated that biosynthetic AuNPs using biomass extracts of _P. aeruginosa_ at 58 \({}^{\circ}\)C and alkaline pH (9.0) resulted in the formation of small spherical nanoparticles with reduced size, as confirmed by UV-Vis and TEM analyses. The preliminary antibacterial screening revealed a statistically significant reduction in  
Figure 6: Effect of ampicillin and bAuNPs on bacterial viability: **(a)** Viability of MSSA expressed in CFU/mL as a percentage of control after treatment with ampicillin, bAuNPs, and both (0.01 mg/L Amp and 0.1 mM bAuNPs); **(b)** Viability of MRSA expressed in CFU/mL as a percentage of control after treatment with ampicillin, bAuNPs, and both (0.1 mg/L Amp and 0.1 mM bAuNPs). NC—Normal condition, i.e., basal medium only; Amp—Ampicillin; bAuNPs—Biosynthetic gold nanoparticles; Both—A mixture of bAuNPs and ampicillin; CFU—Colony-forming units. **\(p<0.01\), ***\(p<0.001\). the growth of MSSA and MRSA when exposed to bAuNPs. Moreover, the combination of ampicillin and bAuNPs exhibited a synergistic effect, significantly reducing bacterial growth and viability, thereby enhancing the individual effects of both agents. Our findings suggest that bAuNPs enhance the penetration of ampicillin into the bacterial cell wall, increasing its efficacy. Additionally, it is possible that bAuNPs enhance the affinity of bacteria to the antibiotic, leading to the disruption of the cell wall. This strategy holds promise for combating antibiotic-resistant bacteria. Furthermore, the use of _P. aeruginosa_ extract as a green reduction system for bAuNP synthesis offers a more sustainable and environmentally friendly alternative to traditional synthesis methods. The valorization of bAuNPs stands as a pivotal achievement of this study. Derived from diverse organisms including plants, fungi, and bacteria, bAuNPs are extracellularly synthesized for efficiency, circumventing intricate intracellular processes and recovery steps. Bacteria, especially _P. aeruginosa_, excel in nanoparticle synthesis due to simple culture conditions and the reduction of metallic ions using biomolecules. Also, the biomass extracts of _P. aeruginosa_ yields bAuNPs with potent antimicrobial potential, boosted by antibacterial compounds like pyocyanin. Adopting _P. aeruginosa_ extracts for bAuNP synthesis transforms antibacterial strategies, augmenting both their direct activity and antibiotic efficacy. This approach gains significance against antibiotic-resistant superbugs. The fusion of biosynthetic AuNPs with low ampicillin concentrations presents a promising synergy, impactful against Methicillin-Susceptible and Methicillin-Resistant _S. aureus_, showcasing a transformative path for combating resistance. Overall, the utilization of biosynthetic AuNPs as carriers for antibiotics, such as ampicillin, holds significant promise in improving antibacterial therapies. The synergistic effects observed in this study highlight the potential of bAuNPs to enhance the efficacy of antibiotics and combat antibiotic resistance. Further advancements in this field could lead to the development of novel therapeutic strategies to address the challenges posed by multidrug-resistant bacteria and contribute to the fight against infectious diseases. In the face of the escalating global health concern posed by antibiotic-resistant bacteria, the strategy employed in this study presents a formidable approach. The fusion of biosynthetic AuNPs with established antibiotics not only showcases the power of interdisciplinary collaboration but also promises to reshape antibacterial therapeutic paradigms. Conceptualization, M.O., S.S. ([PERSON]) and R.F. ; methodology, M.O., M.C.-D. and C.F.P. ; software, M.O. and C.F.P. ; validation, M.O., C.F.P. and R.F. ; formal analysis, M.O., C.F.P. and R.F. ; investigation, M.O., S.S. ([PERSON]), S.S. ([PERSON]), A.G., M.C.-D., P.B., R.F. and C.F.P. ; resources, P.B. and R.F. ; data curation, M.O., C.F.P. and R.F. ; writing--original draft preparation, M.O. and C.F.P.