The present study successfully developed a method based on a dual-functional probe for detecting breast cancer cells MCF-7 by recognizing the MUC1 protein on the cell surface. This method integrated inductively coupled plasma mass spectrometry (ICP-MS) and fluorescence imaging technology, enhancing the sensitivity, specificity, and accuracy of breast cancer cell detection. Additionally, through two-sample Mendelian randomization (MR) analysis, we verified a potential correlation between breast cancer and MUC1 (P