Fluorescent Nanowires Self-Assembled through Host-Guest Interactions in Modified Calcein

Surface patterned pH-sensitive fluorescence using β-cyclodextrin functionalized poly(ethylene glycol)

This paper reports the development of a pH-responsive molecular pattern that shows specific and selective affinity for particular host-guest interactions, and its use as a pH fluorescent sensor. The pH-responsive boronate ester is formed via interactions between the diol group of β-cyclodextrin (CD) and phenylboronic acid of poly(ethylene glycol), and is strategically designed to allow reversible formation of a molecular lining pattern. Printing on a versatile substrate provides a method to monitor the positioning of different molecules by using a pH-responsive boronate ester, allowing specific host-guest interactions on any surface. Confocal laser scanning microscopy, fluorescence spectroscopy, and (1)H NMR results indicate that the assembled CD monolayer can be removed by washing with an acidic pH buffer, demonstrating the presence of a boronate ester connective bridge, which is acid labile. Therefore, visualization of the pH-responsive fluorescence sensor using a rhodamine-CD complex allows straightforward discrimination between different molecules on any substrate, thus facilitating application of this sensor in clinical diagnostics and environmental monitoring.

Synthesis and Self-Assembly of a Nanoscaled Multiarm Polymer Terminated by β-Cyclodextrin

Giant multiarm polymers with and without β-cyclodextrin (β-CD) end groups were synthesized. Further, the former was assembled into nanoparticles via a β-CD/adamantane inclusion complex. The incorporation of an esterase-sensitive linker in the inclusion complex enables the nanoparticles to decompose to the multiarm polymer again through the hydrolysis of ester linkage, making the nanoparticles have the characteristics of multistage nanovectors.