In contrast, P.g-CuNPs at a pH of 8, when tested at a concentration of 100 µg/mL, demonstrated positive inhibition only against E. coli with a ZOI of 6 mm. On the other hand, P.g-CuNPs at a pH of 5, at the same concentration, exhibited positive inhibition with ZOI values of 10 mm, 7 mm, and 6 mm for Salmonella spp, E. coli, and Streptococcus spp, respectively.