A Free-Standing Self-Assembled Tubular Conjugated Polymer Sensor

Abstract

Tubular materials created by self-assembly of small organic molecules have gained great attention recently. Fabrication of tubular structures that have precise dimensions by using conventional self-assembly approaches is extremely challenging. Herein we describe fabrication of a free-standing tubular polydiacetylene (PDA) sensor based on the meniscus-guided self-assembly and polymerization of diacetylene (DA) monomers. The free-standing single PDA tube can be utilized as an unprecedented microcapillary-based sensor system, which requires only a minimum amount (70–140 nL) of an analyte solution. We have observed 4 orders of magnitude more sensitive to analytes than is a conventional PDA sensor when a biotin-functionalized PDA tube is exposed to streptavidin. The microcapillary-based analytical method developed in this study should find great utility not only for PDA sensors but also for other free-standing wire sensor systems.