Conjugated poly(pyridinium salt)s as fluorescence light‐up probes for heparin sensing

Abstract

ABSTRACTBecause of its interaction with diverse proteins, heparin plays an important role in the regulation of various normal physiological and pathological processes. However, heparin overdose can induce some complications such as hemorrhages and thrombocytopenia. Therefore, it is critical to detect and quantify heparin accurately and quickly. Recently, conjugated polyelectrolytes (CPEs)‐based fluorescent probes for heparin sensing have attracted considerable interests. Unfortunately, only few kinds of CPEs such as polyfluorenes derivatives, polythiophene derivatives, are reported and effective in fluorescent assays of heparin by now. This contribution aims to develop a new kind of polyelectrolytes based on poly(pyridinium salt)s derivatives for heparin detection with a light‐up signature. An alternative conjugated poly(pyridinium salt)s (P1) containing carbazole segments in the main chain was designed and synthesized, which are weakly emissive in solution but highly luminescent upon binding with heparin. Fluorescence light‐up probes for heparin detection based on P1 were developed with high selectivity. P1 shows the similar fluorescence response toward heparin both in a broad pH range of about 3–12 and in the presence of various competing anions. Heparin quantification with a practical calibration range (0–14 µM) covering the whole therapeutic dosing levels (0.2–1.2 U mL−1, 1.7–10 µM) is realized based on the polymer probe. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40933.