Microgel-Based Inks for Paper-Supported Biosensing Applications

Abstract

As a first step for the development of biosensing inks for inexpensive paper-based biodetection, we prepared paper strips printed with carboxylic poly( N-isopropylacrylamide) microgels that were modified either with an antibody or with a DNA aptamer. We found that the antibody and the DNA aptamer retained their recognition capabilities when coupled to microgel. The printed microgel remains stationary during chromatographic elution while the microgel-supported molecular recognition elements are accessible to their intended targets present in the elution solution. Our work indicates that microgels, large enough to isolate the biosensors from the paper surface, are sufficiently hydrophilic to be wetted during chromatographic elution, exposing the gel-supported affinity probes to their targets.

Supramolecular Polymer Networks: Preparation, Properties, and Potential

“…They find multiple applications in drug delivery [286], biosensing [287], catalysis [288], and regenerative medicine [289]. Microgels are particularly useful for the encapsulation of living cells, because the microgel matrix can mimic the natural extracellular matrix very well and because microgel particles can be handled very easily by syringes and pipettes and are injectable [290].…”

Microgels by Precipitation Polymerization: Synthesis, Characterization, and Functionalization

“…Su et al [120] reported modification of PNIPAAm microgels with antibody or with a DNA aptamer. The PNIPAAm microgels carrying carboxyl groups were prepared as the first step.…”

Biomolecule immobilization techniques for bioactive paper fabrication

“…Polyamide-epichlorohydrin (PAE) wet-strength resin can influence both biosensor immobilization and activity. Cationic PAE promotes the adsorption of DNA aptamers, but bound sensors are denatured and thus inactive [16]. It seems that paper treated with wet-strength resin may be a good substrate for the direct immobilization of biosensors.…”

“…They concluded that colloidal microgels based on poly(N-isopropylacrylamide) (PNIPAM) were superior because PNIPAM results in little non-specific protein binding. Su et al [16] first coupled streptavidin to a carboxylated PNIPAM microgel in the presence of N-ethyl-N-(dimethylaminopropyl)carbodiimide, then covalently coupled biotin-terminated DNA aptamers or biotin-terminated antibodies to the above-mentioned streptavidin-substituted PNIPAM microgel. They observed that simply air-drying the microgels after spotting them on filter paper could immobilize the gels.…”