A critical assessment of ionic liquid-based aqueous biphasic systems for biomolecules extraction and CO₂ absorption

Ionic liquids (ILs) are green designer solvents that have gained research interest in industrial applications, including solvent chemistry, catalysis, and electrochemistry. Recent advances in ionic liquid-based aqueous biphasic systems (IL-ABSs) have broadened their biological applications. This review discusses the state-of-the-art of its biotechnological application in biomolecules recovery and phase separation mechanism. The prospects of ILs as green solvents and their toxicity and applicability in carbon dioxide (CO₂) capture are discussed. The correlation between the structures and toxicity of ILs is also provided, with a special emphasis on the synthesis of safer ILs. This review examines the significance and techniques in recovering and reusing phase-forming agents such as ILs. The incorporation of machine learning (ML) algorithms to predict the toxicity and CO₂ capture properties, as well as the scaling up of IL-ABSs, is also explored.