Peptide‐Based Organic‐Inorganic Hybrid Self‐Assemblies for Ultrasensitive and Visual Detection of Heparin

Abstract Accurate point‐of‐care testing (POC) of low molecular weight heparin ( LMWH ) can efficiently promote its rational use in the prevention and treatment of thromboembolic diseases but still remain a key challenge. Herein, a peptide‐derived supramolecular self‐assembly system is reported for ultrasensitive and visual detection of LMWH . Two different peptides are designed and modified by gold nanocluster ( AuNC ) and tetraphenylethene ( TPE ), respectively, to co‐assemble into nanoparticles, enabling the loading and co‐recognition of LMWH . Owing to two‐wavelength emission from the co‐assemblies at 624 and 460 nm that is highly sensitive to LMWH , such assemblies realize ratio‐type detection of LMWH . The sensitivity of the AuNC‐ peptide to LMWH significantly increases when co‐assembling with TPE ‐peptide, while that of TPE ‐peptide maintains in a high level, enabling a balanced and ultrahigh sensitivity of both two fluorophores. Such self‐assemblies reach an extreme limit of detection of 0.0004 IU mL −1 and realize dramatic fluorescence color change when loading trace concentration of LMWH , which can be simply distinguished by naked‐eye. Thus, by preparing Pep2 @ AuNC / TPE ‐ Pep1 test strips the POC testing of LMWH in real thrombus patient samples has achieved. It provides a promising tool for on‐site and real‐time monitoring of anticoagulation therapy to guide LMWH titration into the therapeutic window.