Tumors are one of the major diseases threatening human health, among which solid tumors account for a considerable proportion. Nectin-4, as an important cell adhesion molecule, shows a highly expressed state in various solid tumors. In triple-negative breast cancer, the high expression rate of Nectin-4 can reach more than 50%, and it is closely associated with tumor invasion, metastasis and poor prognosis. Relevant studies have shown that the five-year survival rate of triple-negative breast cancer patients with high expression of Nectin-4 is significantly lower than that of patients with low expression. In urothelial carcinoma, the positive expression rate of Nectin-4 is also relatively high, reaching 40%-60%, and it is a highly potential target for tumor treatment and diagnosis. Its abnormal expression in solid tumors has opened up a new direction for the early diagnosis and targeted therapy of tumors. However, at present, the precise diagnosis and effective treatment of solid tumors with high expression of Nectin-4 still face many challenges. There is an urgent need for new technologies and methods to improve the diagnosis and treatment level in order to improve the prognosis of patients. Therefore, this study aims to develop a method targeting the Nectin4 bicyclic peptide to achieve non-invasive visualization of Nectin4 expression in tumors. This approach may also contribute to the formulation and optimization of clinical treatment strategies