Review on green Amino acid–fatty acid amphiphiles and metallosurfactants: Self-assembly and applications

A unique class of Bio-based surfactants, known as amino acid–fatty acid amphiphiles, enables finely tunable amphiphilicity by combining the hydrophilic properties of amino acids with the hydrophobicity of fatty acids. Their molecular structure facilitates the formation of micelles, vesicles, lamellae, and other supramolecular assemblies, characterised by vigorous surface activity and intrinsic biodegradability. These systems are helpful in industrial formulation science, pharmaceutical delivery systems, catalytic processes, and environmental technologies due to their assembly nature. Metallosurfactants, in which metal–ligand interactions strengthen aggregate integrity and introduce catalytic, redox, or photophysical functions without sacrificing interfacial performance, are created when transition-metal ions coordinate with the amphiphilic headgroups. With a focus on structure-dependent aggregation and functional output, this review summarises recent developments in synthetic techniques, structural design principles, self-assembly mechanisms, and physicochemical characteristics of amino acid-based amphiphiles. In addition to sustainability factors such as biodegradability and toxicity, the applications of native amphiphiles and their metallated derivatives are critically evaluated for detergency, catalysis, nanomedicine, and pollutant remediation. All of the aforementioned advancements highlight the molecules’ potential as workable building blocks for sustainable surfactant technologies of the future.