Synthesis of a novel cobalt containing metallogel using 5ʹ-adenosine monophosphate as a small molecule hydrogelator

Abstract

Hydrogels are attractive biomaterials, due to their soft nature resembling the biological tissues and ability to absorb a large amount of water inside its matrix. Subsequently hydrogels have found interesting applications in biomedical areas, tissue engineering, targeted drug delivery, and several others. Most of the molecular architectural designs for the hydrogelators are based on polymers which form entangled fibril networks through a combination of noncovalent interactions such as π- π interactions, hydrogen bonding and vander Waals interactions that can entrap large volume of water. On the other hand, native biomolecules, such as carbohydrates, peptides and nucleic acids form an exclusive class of small molecule hydrogelators. Equipped with various noncovalent binding sites, nucleotides represent a naturally occurring gelator, that can bind metal ions through coordination bonds. The biocompatibility and stimuliresponsiveness of the resultant coordination polymer hydrogels can be harneseed towards fascinating functional materials taking advantage of the inherent characteristics of both the metal and organic counterparts. Herein, we report the synthesis of a novel coordination polymer hydrogel by coordinating cobalt ions (Co2+) with 5ʹ-AMP. A blue color gel was produced as a consequence of heating the aqueous solutions of both metals as well as gelator mixed in the molar ratio of 1:1 (v/v). This coordination polymer hydrogel is expected to exhibit diverse magnetic, electric, and bio-mimetic properties that might influence a wide range of applications such as enzyme mimetics, magnetic soft materials and energy applications. There are many processes in which we need enzymes to work as catalysts but their limited availability often limits their use. Esterase enzyme is one such hydrolase enzyme that is used to catalyze the conversion of ester into acid and alcohol. Although we performed the enzymatic assay for esterase activity with the synthesized hydrogel, we could not obtain the desired outcome. As Co2+ metals are known to catalyze a diverse class of organic transformations, we expect these hydrogels to be utilized as heterogeneous catalysts in a biocompatible environment.