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

Abstract

AbstractAccurate 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.