An optimal radiosensitizer with improved tumor retention have an important effect in tumor radiation therapy. Herein, gold nanoparticles (Au NPs) and drug containing, mPEG-conjugated CUR (mPEG-CUR), self-assembled NPs (mPEG-CUR@Au) were developed and evaluated as a drug carrier and radiosensitizer in a breast cancer mice model. As a result, cancer therapy efficacy was improved significantly by applying all-in-one NPs to achieve synchronous chemoradiotherapy, as evidenced by studies evaluating cell viability, proliferation, and ROS production. In vivo anticancer experiments showed that the mPEG-CUR@Au system improves the radiation sensitivity of 4T1 mammary carcinoma and completely abrogates breast cancer. This article is protected by copyright. All rights reserved.