Application of a Near-Infrared Fluorescence Probe\nBased on Perylene Bisimide in the Detection of Heparin

Heparin\nis widely used to treat thrombosis because it is an effective\nanticoagulant. However, excessive use of heparin can lead to an increased\nrisk of bleeding, which makes the quantitative detection of heparin\nvery important. An amphiphilic perylene bisimide molecule (denoted\nPBI-9) was developed, which presented a near-infrared emission peak\nat 730 nm when it was aggregated. PBI-9 has been utilized in the detection\nof heparin, as the pyridine cation in PBI-9 binds strongly to highly\nsulfated heparin through electrostatic interactions. Charge neutralization\ntriggers the self-assembly of PBI-9, which leads to an emission peak\nshift from 540 nm to 690 nm, corresponding to monomeric emission to\nexcimer emission. This shift was applied for the detection of heparin.\nImportantly, the interaction between PBI-9 and heparin is not affected\nby protamine, resulting in high selectivity and minimal interference.\nPBI-9 is a promising tool for detecting heparin in clinical settings\nafter excess heparin has been neutralized by protamine.