Synthesis and Characterization of Rubisco–Magnesium Complexes for Potential Gas Adsorption Applications

Abstract

Enzyme-based complexes represent an emerging class of functional adsorbents combining specificity and environmentally friendly potential. We proposed the development of metal-enzyme-based complexes that leverage the unique properties of magnesium metal to increase enzyme-structure integration for the formation of hybrid porous matrices with the potential to modulate targeted gas adsorption under mild conditions. For this, ribulose-1,5-bisphosphate carboxylase oxygenase (RuBisCO), a carboxyl-lyase responsible for carbon fixation in the Calvin–Benson–Bassham cycle, was used as a scaffold that supported stable coordination of its amino acids, water, and/or phosphate groups with magnesium ions. Time- and dose-dependent synthesis and characterization of the resulting metal–enzyme complexes, performed through electron microscopy, infrared spectroscopy, and X-ray diffraction, unraveled the high-resolution structure formation. Magnesium integration led to crystal lattice formation, resulting in complexes of defined porosity and size, as evaluated through particle diffraction studies helping connect metal–enzyme synthesis time and ratio with the observed physicochemical properties. Preliminary gas adsorption testing with N2 and CO2 conducted using both physisorption and static chemisorption methods demonstrated that the metal–enzyme complexes exhibit measurable gas uptake behavior, thus indicating potential for gas interaction and adsorption under controlled conditions. These findings lay the groundwork for further exploration of metal–enzyme hybrids as tunable, bio-inspired materials for gas adsorption, with future studies needed to optimize performance and assess such complexes potential in real-world applications.