The potential use of antioxidants for photodynamic therapy (PDT) is investigated in this study. PDT causes reactive oxygen species (ROS)-mediated cell death; on the contrary, antioxidants scavenge ROS. The use of a photosensitizer along with an antioxidant photosensitizer compensates for the loss of ROS due to the use of antioxidant, eventually leading to cell death. In this work, for PDT and photothermal therapy (PTT), we have combined the photosensitizer IR 792 perchlorate dye with the antioxidants alpha-tocopherol (A) and p-coumaric acid (C) encapsulated in a polymeric nanocarrier (AC IR NPs). We have reported the synthesis of AC IR NPs using poly lactic-co-glycolic acid (PLGA) by nanoprecipitation method. The size of the polymeric nanoparticles was found to be 80.4 ± 15.6 nm, with a spherical morphology observed by scanning electron microscopy and transmission electron microscopy. The synthesized AC IR NPs demonstrated good biocompatibility in fibroblast cell lines (L929). Furthermore, the efficacy assessment of the as prepared nanosystem in vitro on breast cancer cell lines (4T1) revealed a significant cell death of nearly 80%. This could be attributed to the ROS generation leading to oxidative stress and inhibition of metastasis. This study provides evidence that the combination of antioxidant drugs along with photosensitizers have the potential to be an effective therapy for treating triple negative breast cancer.