Antifungal activity of gold nanoparticles synthesized by laser ablation with blue diode laser photodynamic activation against Candida albicans.

Infections caused by Candida albicans pose a serious challenge in healthcare, particularly due to increasing resistance to conventional antifungal agents. Photodynamic therapy (PDT), which combines light, photosensitizers, and oxygen, offers a promising alternative solution. This study aimed to evaluate the antifungal effectiveness of gold nanoparticles (AuNPs) synthesized via laser ablation, as well as the effect of photodynamic activation using a blue diode laser (403 nm) on the growth of C. albicans. Samples were divided into four groups: (1) control, (2) Candida albicans treated with three concentrations of AuNPs (100, 150, and 200 ppm), (3) Candida albicans irradiated with a 403 nm blue diode laser at four exposure times (90, 120, 150, and 180 s), and (4) Candida albicans treated with AuNPs combined with laser irradiation. Antifungal activity was assessed using the Total Plate Count (TPC) method, with results expressed in CFU/mL. Data were analyzed using a two-way factorial ANOVA followed by Tukey’s post hoc test (p < 0.05). The results showed that AuNPs alone reduced colony counts by up to 28.63% at 200 ppm. However, the combination of AuNPs and blue diode laser irradiation significantly enhanced antifungal activity. The highest reduction (83.36 ± 7.84) % was observed at 150 ppm AuNPs with 180 s of irradiation, corresponding to an energy density of 9.17 J/cm². These findings highlight the potential of combining AuNPs with photodynamic therapy as an effective and environmentally friendly alternative for treating fungal infections.