title: Label-free multimodal protease detection based on protein/perylene dye coassembly and enzyme-triggered disassembly.
abstract: The development of novel assays for protease sensing plays an important role in clinical diagnostics and therapeutics. Herein, we report a supramolecular platform for label-free protease detection, based on protein/dye self-assembly and enzyme-triggered disassembly. In a typical case, coassembly of protamine sulfate and perylene dye via electrostatic attractions and π-π interactions caused significant colorimetric and fluorescent responses. Subsequent addition of trypsin was found to cleave the amide bonds of protein, triggering the dissociation of protein/dye aggregates and the release of perylene dyes. The enzyme-triggered disassembly was transduced into multiple readouts including absorption, fluorescence, and polarization, which were exploited for trypsin detection and inhibitor testing. This assay was also used for turn-on fluorescence detection of cathepsin B, an enzyme known to be overexpressed in mammalian cancer cells. The integration of supramolecular self-assembly into enzyme detection in this work has provided a novel label-free biosensing platform which is highly sensitive with multimodal readouts. The relative simplicity of the approach avoids the need for time-consuming substrate synthesis, and is also amenable to naked eye detection.
authors.affiliation: Department of Materials, Department of Bioengineering, and Institute for Biomedical Engineering, Imperial College London , Exhibition Road, London SW7 2AZ, United Kingdom.
authors.forename: Yiyang
authors.initials: Y
authors.lastname: Lin
authors.forename: Robert
authors.initials: R
authors.lastname: Chapman
authors.forename: Molly M
authors.initials: MM
authors.lastname: Stevens
mesh_terms: D000818:Animals; D015374:Biosensing Techniques / Q000379:methods*; D002401:Cathepsin B / Q000032:analysis*; D002417:Cattle; D005453:Fluorescence; D005456:Fluorescent Dyes / Q000737:chemistry*; D006801:Humans; D010569:Perylene / Q000737:chemistry*; D012474:Salmon; D013050:Spectrometry, Fluorescence / Q000379:methods; D014357:Trypsin / Q000032:analysis*
chemical_list: D005456:Fluorescent Dyes; D010569:Perylene; D014357:Trypsin; D002401:Cathepsin B