This study aims to assess the effectiveness of Antimicrobial Photodynamic Therapy (aPDT) using phenothiazine photosensitizer (PS) combined with gold nanoparticles (DMMB-AuNPs) in treating S. aureus-contaminated wounds on the dorsum of rats. Twelve Wistar rats were divided into four groups: Control, LED, DMMB-AuNPs, and DMMB-AuNPs + LED. DMMB-AuNPs were prepared using DMMB (300 ng/mL) and 5 nm diameter AuNPs (~ 5.5E + 13 particles/mL). The light source was a red LED (12 J/cm