# Diversity of Potential (Bio)Technological Applications of Amino Acid-Based Ionic Liquids
## 2 Bioapplications of AA ILs: An Overview
### Other Applications
#### 2.10.5 AA ILs as Surfactants  
AA IL surfactants are particularly valuable in green chemistry and advanced materials due to their customizability and environmental benefits. They find applications as emulsifiers in oil-water systems for cosmetics, pharmaceuticals, and enhanced oil recovery; as templating agents for the preparation of nanomaterials and mesoporous structures; as advanced detergents; and as stabilizers for dispersing nanoparticles or stabilizing colloidal systems. For example, choline N-lauroyl-AAs, self-assembling fatty AA-based surfactants, are significantly superior to conventional ionic surfactants such as sodium dodecyl sulfate and sodium dodecyl benzene sulfate, while being less toxic to human cells in vitro [295]. [PERSON] et al. proposed task-specific surfactants based on AA propyl or butyl ester cations and a lauryl sulfate anion [296]. These ILs form closed bilayer structures, with self-assembly controlled by a fine balance of solvophobic effects and ionic arrangements via hydrogen bonding and electrostatic interactions [297]. These surfactants show excellent potential for mitigating harmful algal blooms in seawater and serving as templates for the shape- and size-specific synthesis of CeO\({}_{2}\) nanomaterials. Another example is dodecyl betaine N-acetyl glycinate, an IL capable of forming stable micelles in water. In this case, strong interactions between the anion and water through hydrogen bonding contribute to the micellar solubility, allowing the dissolution of hydrophobic drugs in water [298]. Interestingly, [PERSON] et al. synthesized mesoporous silica with uniform hollow triangular prism morphology and high specific surface area using [N\({}_{1111}\)][Gly] and a supramolecular organogel N-lauroyl-L-glutamic acid di-n-butylamide as co-templates [299]. Using the same co-templates, [PERSON] et al. fabricated cactus rod-like mesoporous alumina [300]. Additionally, ILs based on cations such as 1-(2-methoxyethyl)-3-methylimidazolium or choline and anions like Asp or Glu, mixed with monoolein, form liquid-crystalline matrices with three-dimensional continuity and periodicity. The cubic lattice constant of these matrices can be tuned from 88 to 100 A by designing specific AAILs [301]. Mesoporous \(\gamma\)-Al\({}_{2}\)O\({}_{3}\) impregnated with [Emim][Gly] demonstrated optimal textural properties as a CO\({}_{2}\) capture material [302]. On the other hand, silica-coated magnetic nanoparticles modified with [Emim][Pro] displayed strong chiral recognition abilities, making them suitable for the direct separation of chiral AAs using centrifugal chiral chromatography [303]. [PERSON] et al. reported that SBA-15 modified with 1-methyl-3-(3-(trimethyl)propyl) imidazolium lysinate achieved 99% immobilization efficiency for porcine pancreatic lipase. Strong carrier-enzyme interactions prevented leaching, preserving 96% of the enzyme's catalytic efficiency even after five cycles [304]. Similarly, a nanocomposite based on an ordered graphitized mesoporous carbon surface modified with [Emim][Ala] was found to be an excellent support for tyrosinase biosensors. These biosensors showed a linear response for phenol concentrations from 0.1 to 10 umol\(\cdot\)L\({}^{-1}\) with a low detection limit of 20 nmol L\({}^{-1}\) and retained 90% of their initial activity after 21 days of storage [305]. Additionally, magnetic iron oxide nanoparticles stabilized with silane ligands containing [Ch][Gly] or [Ch][Lys] were shown to be efficient catalysts for Knoevenagel condensation reactions [306]. [PERSON] et al. proposed a novel two-step reduction procedure for the synthesis of gold nanoparticles (AuNPs) using 1-dodecyl-3-methyl imidazolium tryptophan ([C\({}_{12}\)mim][Trp]) or [Emim][Trp] [307]. Both the cation and anion of these ILs contribute to AuNP stabilization, with the longer alkyl chain of [C\({}_{12}\)mim][Trp] providing superior stability.