OICC Press Journal of Nanostructure in Chemistry 2193-8865 16 4 2026 08 31 A Eu-MOF Nanoarchitectured Electrochemiluminescent Sandwich Immunosensor for ProGRP Quantification in Serum and Pleural Effusion 10.57647/jnsc.2026.1604.20 EN Linlin Luo The Second Department of Respiratory Disease, Jiangxi Provincial People's Hospital (The First Affiliated Hospital of Nanchang Medical College), Nanchang, 330006, Jiangxi Province, China Chao Xu Department of Orthopedics, Shangrao Municipal Hospital (Affiliated Shangrao Municipal Hospital of Nanchang Medical College), Shangrao, 334000, China Sicong Jiang The Second Department of Respiratory Disease, Jiangxi Provincial People's Hospital (The First Affiliated Hospital of Nanchang Medical College), Nanchang, 330006, Jiangxi Province, China Yuxuan Xing Department of Thoracic Surgery, The First Affiliated Hospital of Soochow University, Suzhou, 215006, China Zhiqian Zhao Department of Thoracic Surgery, The First Affiliated Hospital of Zhengzhou University, Zhengzhou University, Zhengzhou, 450000, China Shuo Li Department of Respiratory Medicine, The First Affiliated Hospital of Shandong First Medical University & Shandong Provincial Qianfoshan Hospital, Shandong Institute of Respiratory Diseases, Featured Laboratory of Respiratory Immunology and Regenerative Medicine in Universities of Shandong, Jinan Clinical Research Center for Respiratory Disease, Jinan 250014, China Journal Article 2026 08 31 Effective clinical management of small cell lung cancer (SCLC) requires sensitive and matrix-tolerant quantification of pro-gastrin-releasing peptide (ProGRP). Herein, we report a nanoarchitectured electrochemiluminescence (ECL) sandwich immunosensor that combines a three-dimensional reduced graphene oxide/gold (3D-rGO@Au) capture interface with a luminescent europium metal-organic framework (Eu-MOF) signal probe labeled with Ab2 for ProGRP measurement in serum and pleural effusion. The Eu-MOF formed uniform octahedral particles and provided efficient antenna-effect-assisted ECL emission with K₂S₂O₈ as the coreactant, while the 3D-rGO@Au interface increased antibody loading and accelerated interfacial electron transfer. The assay achieved a detection limit of 0.035 pg mL⁻¹ over a broad linear range, showed satisfactory recovery in two clinical matrices, and agreed well with commercial ECLIA measurements. Beyond combining two previously reported material families, the main contribution of this work is the clinically oriented integration of a high-loading conductive interface, a Eu-MOF luminophore probe, mechanistic ECL/CV/EIS validation, and real-sample verification for ProGRP detection.