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

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.