Aptamer&MOF-functionalized Multichannel Paper Chip for Point-of-care Testing of Small Extracellular Vesicle Membrane Protein Profile

Small extracellular vesicles (sEVs) membrane protein profile (sEVpp) is a novel biomarker for cancer, and it can reveal the in-depth phenotype information. The point-of-care testing (POCT) of sEVpp holds great significance for mass screening of cancer, so the cost-effective and simple detection methods of sEVpp are urgently demanded. Herein, we constructed a paper-based multichannel sEVpp POCT device (sEVpp-PAD) enabled by functional DNA probes and metal-organic framework (MOF). The core components are aptamer/MOF-modified paper chips. The modified aptamers can immunocapture the sEV expressing corresponding proteins, while the modified MOF can provide abundant sites for aptamer-modification, reduce the nonspecific protein absorption, and act as reference for ratiometric detection. Simply powered by two syringes, the sEVpp-PAD can efficiently capture sEVs expressing corresponding protein from cell culture media and sera. Furthermore, a detection probe (DP) consisted of CD63 aptamer and G-quadruplex was developed for the colorimetric detection of captured sEVs. Utilizing this device, the sEVpp in various hepatocellular carcinoma cell culture medium and, more importantly, in human sera can be accurately determined, only with $2 device, $0.2 detection reagents and 1.8 h procedure. This simple strategy for sEVpp detection can innovatively promote the POCT and subtyping of cancer based on sEV-related liquid biopsy. (c) 2025 Published by Elsevier B.V. on behalf of Chinese Chemical Society and Institute of Materia Medica, Chinese Academy of Medical Sciences.