Oligonucleotide-functionalized hydrogels as stimuli responsive materials and biosensors

Abstract

Hydrogels are crosslinked hydrophilic polymers that undergo swelling in water. The gel volume is affected by many environmental parameters including temperature, pH, ionic strength, and solvent composition. Therefore, these factors have been traditionally used for making smart hydrogels. DNA, on the other hand, is a special block copolymer. Incorporation of DNA within a hydrogel network can have several important effects. For example, DNA can serve as a reversible crosslinker modulating the mechanical and rheological properties of a hydrogel. Second, DNA can selectively bind to a variety of different molecules. Attaching these binding DNAs inside (aptamers) the hydrogel makes it possible to expand the range of stimuli to chemical and biological molecules. At the same time, the gel matrix can also improve DNA-based sensors and materials. For example, the hydrogel can be dried for storage and rehydrated prior to use and the immobilized DNAs are protected from nuclease cleavage. The gel backbone property can also be tuned to affect the interaction between DNA and other molecules. The rational functionalization of DNA in hydrogels has generated a diverse range of smart materials. In the last 15 years, the field has made tremendous progress and some of the recent developments have been summarized in this review. Challenges and possible future directions are also discussed.

Aptamer-Functionalized Hydrogel Microparticles for Fast Visual Detection of Mercury(II) and Adenosine

“…To effectively protect these molecules and interface them with devices at the same time, much research effort has been devoted to developing materials for biosensor immobilization, including on gold, 2,3 silica, 4 carbon nanotubes, 5,6 graphene oxide, 7,8 lipid bilayers, 9 paper materials, 10 and hydrogels. 11,12 Hydrogels are particularly attractive for making optical sensors. [13][14][15][16][17][18][19] Biomolecular immobilization occurs not only on gel surface but also throughout the whole gel matrix, allowing for high loading capacity.…”

Visual optical biosensors based on DNA-functionalized polyacrylamide hydrogels

“…An acrydite DNA has a similar reactivity as free acrylamide monomers, allowing a high incorporation efficiency [43]. While the field of DNA-functionalized hydrogels began in 1996 [44], most of the developments have occurred in the past ten years [45][46][47][48]. In this article, we only provide a concise review of recent developments in visual detection using DNA-functionalized hydrogels.…”

Molecularly Imprinted Polymers with DNA Aptamer Fragments as Macromonomers

“…For easy handling and good template accessibility, MIP hydrogel nanoparticles (or nanogels) were prepared in this study. [24][25][26][27][28][29][30][31] …”