In this study, pristine silver-doped zinc oxide (Ag–ZnO) and Plumbago zeylanica leaf extract (PZE) incorporated with Ag–ZnO, along with the additional material of cetyltrimethylammonium bromide (CTAB)-assisted Ag–ZnO nanorods, were synthesized and extensively characterized. The basic properties of the samples were studied and optimized. Gas sensing measurements were conducted, and the obtained results were thoroughly interpreted. The study includes demonstrating and examining pure Ag–ZnO, PZE-added Ag–ZnO, and CTAB-assisted Ag–ZnO. Notably, the presence of CTAB exhibited a favorable effect on the Ag–ZnO, indicating an enhanced isopropyl alcohol gas sensing response time of 20 s at 15 ppm within an ambient temperature. Additionally, improvements in selectivity and reduced sensor resistance in current (nanoampere - nA) were observed in CTAB-assisted Ag–ZnO. The sensing mechanism was investigated, focusing on the depletion layer of Ag–ZnO with the surfactant. The work emphasizes the sensing abilities of PZE-assisted Ag–ZnO and CTAB Ag–ZnO, highlighting the significance of these noble metals in systematic gas sensing applications.