Visual Detection of pH and Biomolecular Interactions at Micromolar Concentrations Aided by a Trivalent Diacetylene-Based Vesicle

摘要

A trivalent tris-(alkylenediynoic acid) is developed as a new monomer to prepare a poly(tris-(diacetylene)). Alkylenediynoic moieties, covalently linked to the gallic acid, lead to a high propensity for polymerization, resulting in blue poly(tris-(diacetylene)), within less than 20 s of UV irradiation as aq. vesicle solution and as thin film. The vesicle undergoes reversible thermochromism between room temperature and 95 degrees C. The corresponding chromism changes are blue-to-red-to-orange during heating and reverse on cooling. This reversible chromism also occurs to thin film between room temperature and 220 degrees C. The polymerized aq. vesicle exhibits pH-induced chromism in the alkaline range. In order to identify polymerization-induced chromatic transitions beneficial to a biosensing process, derivatization of the monomer with -d-mannopyranoside moieties is conducted. Chromatic properties of sugar-derivatized tris-(alkylenediynoic acid) vesicle are established first. Poly(tris-(diacetylene)) vesicles, prepared from either pure or mixed monomer systems, exhibit blue phase, which do not undergo change in chromism when the sugar-lectin interaction is initiated. Whereas, when the monomer vesicle is prepared in the presence of the lectin and polymerized subsequently, chromism of the resulting poly(tris-(diacetylene)) solution is pink, as a result of ligand-lectin interaction. The chromism change can be conducted at approximate to 10 x 10(-6) m each of both vesicle and the lectin.