A Hierarchical Enzyme-Mimetic Supramolecular Catalyst Derived from Folic Acid-KOH/Cu Hydrogel: Self-Assembly Study and Mechanism for Enhanced Oxidation of Phenolic Compounds
Year: 2025
Type: article
Abstract: High Resolution Image Download MS PowerPoint Slide The rational design of enzyme-mimetic catalysts through supramolecular self-assembly offers a promising avenue for robust, cost-effective, and tunable green catalysis avoiding biological limitations. In this work, we demonstrate the development of a hierarchical supramolecular catalyst derived from folic acid (FA), a natural low-molecular-weight gelator (LMWG), through a two-step process involving pH-triggered self-assembly and copper(II)-induced hydrogelation. FA was first solubilized in aqueous KOH (pH ≈ 8.5) to form folate ions, which underwent time-dependent self-assembly into fibrillar structures. Upon addition of Cu(II), these self-assembled structures cross-linked into a stable hydrogel matrix ( FA-KOH/Cu ). The resulting xerogels, derived from both fresh and aged FA-KOH solutions, displayed distinct morphologies and catalytic performances. Aged hydrogels ( FA-KOH/Cu-Aged ) exhibited higher mechanical strength and catalytic activity than their freshly prepared counterparts ( FA-KOH/Cu-Fresh ), owing to the development of a flake-like microstructure with enhanced surface area and redox accessibility. These xerogels efficiently catalyzed the oxidative coupling of 2,4-dichlorophenol and 4-aminoantipyrine, mimicking laccase activity. Kinetic studies revealed enzyme-like Michaelis-Menten behavior, with the FA-KOH/Cu-Aged xerogel showing superior catalytic efficiency ( k cat / K m = 235 × 10 –5 (g·L –1 ) −1 ·s –1 ) compared to the FA-KOH/Cu-Fresh xerogel ( k cat / K m = 399 × 10 –5 (g·L –1 ) −1 ·s –1 ). This work highlights how aging-guided hierarchical nanostructure formation critically modulates catalytic efficiency and substrate accessibility. Overall, our findings demonstrate a biomimetic design framework that integrates molecular self-assembly, metal coordination, and supramolecular material engineering to develop sustainable and responsive catalysts for environmental applications.
Source: ACS Omega
Authors: Sunil Rathod, Vaishali R. Gudda, Bappaditya Roy
Institutions: Amity University, Amity University Mumbai
Language: English
Subfield: Biomaterials
Field: Materials Science
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $1,935
OpenAlex ID: W4416435679