Session: Analytical Division Poster:

Here we present a highly sensitive fluorescence turn-on probe for detection of heparin based on multisite-binding induced fluorescence quenching strategy. The probe employs a cationic polymer PDDA as a multisite binder for strong binding with an anionic perylene derivative PDI1. PDI1 was designed with four negative charges that allow multisite binding with PDDA in aqueous solution. The optical properties of PDI1 and the binding of PDI1 with PDDA were investigated using UV-vis and fluorescence spectroscopy. Compared to the control compound-a perylene derivative PDI2 with two negative charges, PDI1 itself in aqueous solution is much more fluorescent due to the charge repulsion and chirality of the aspartic side chains. Upon the addition PDDA, the fluorescence decreased significantly duo to the formation of non-fluorescent PDDA:PDI1 aggregates. The PDDA:PDI1 aggregates were further demonstrated as a fluorescent turn-on probe for detection of heparin and signal to noise ratio of 400 can be achieved compared to 100 of that for PDDA:PDI2 aggregates. This displacement probe showed an attractive performance compared to most of the methods reported previously and a detection limit of 0.0005 U/mL was achieved for heparin in aqueous buffer. The probe was further applied to detect heparin in human serum with dilution.

Kenneth Hunter

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