Sensitive Detection Of Protamine Based On A Yellow Emission Fluorophore

In this study, a novel p-hydroxybenzylidene-imidazolidone derivatives-based probe CBX (abbreviation of the synthetic probe) is designed and synthesized for sensitive detection of protamine. CBX emits fluorescence at 569 nm and a large Stokes shift of 114 nm is observed. Since protamine can induce the aggregation of negatively charged CBX, the designed probe shows excellent fluorescent response to protamine. Due to stronger electrostatic interactions between heparin and protamine, protamine prefers to unite with heparin rather than the probe after the addition of heparin, so the fluorescence of CBX decreases and realizes the detection of heparin. Comparing to other reported probes, CBX shows lower background interference, better sensitivity and higher stability. Limit of detection for protamine and heparin is calculated as 0.034 and 0.028 mu g mL(-1), respectively. Moreover, the detection of protamine by CBX is not interfered by other glycosaminoglycans.