# Diversity of Potential (Bio)Technological Applications of Amino Acid-Based Ionic Liquids
## 2 Bioapplications of AA ILs: An Overview
### Other Applications
#### 2.10.2 Electrochemistry  
ILs play a crucial and versatile role in electrochemistry due to their unique physicochemical properties. Among them, AA ILs are particularly attractive due to their safety profile. With high conductivities, wide electrochemical stability windows, low volatility, and non-flammability, AA ILs such as [Ch][AAs], [Emim][AAs], and 1-butyl-3-vinylimidazolium (VilimC\({}_{4}\))-based ILs such as [VilimC\({}_{4}\)][His], [VilimC\({}_{4}\)][Lys], [VilimC\({}_{4}\)][Ser], and [VilimC\({}_{4}\)][Gly]--used either in pure form or mixed with organic solvents--have found applications as electrolytes in energy storage devices such as supercapacitors and batteries [275-279].  
AA ILs also show great promise in electrocatalysis due to their ability to stabilize reaction intermediates. For example, in CO\({}_{2}\) reduction reactions, they act as both a reaction medium and a co-catalyst. Furthermore, their ability to dissolve various substances and form stable electrode interfaces enhances the performance of electrochemical sensors.  
In bioelectrosensing, AA ILs are particularly effective because they can specifically interact with target molecules (e.g., glucose, CO\({}_{2}\), etc.), thereby improving sensitivity and selectivity. For example, an electrochemical biosensing platform combining [Bmim][Pro] with a carbon nanotube composite provides excellent stabilization for glucose oxidase, maintaining high enzyme activity toward glucose with a linear range of 0.05-0.8 mM and a detection limit of 5.5 \(\upmu\)M [280]. On the other hand, a sensitive detection of ammonia (lower limit 1 ppm) at room temperature has been reported for a device based on a cellulose membrane with incorporated [Emim][Pro] [281]. In addition, N-doped graphene quantum dots assembled on [Hmim][Trp] micelles construct a novel fluorescence \"turn on/off\" probe for the detection of Cu(II) and levodopa [282]. Under optimized conditions, Cu(II) and levodopa exhibited strong linear relationships within the concentration ranges of 0.051-16.00 \(\upmu\)g/mL and 0.55-5.00 \(\upmu\)g/mL, respectively, with LODs of 0.017 \(\upmu\)g/mL and 0.16 \(\upmu\)g/mL. Interestingly, poly-1-vinyl-3-butylimidazolium glutamate acid serves as a stable up-conversion fluorescence probe for H\({}_{2}\)O\({}_{2}\)-regulated Fe(II)/Fe(III) speciation. The LODs for Fe(II) and Fe(III) were reported to be 6.16 ng/mL and 4.48 ng/mL, respectively [283].  
The suitability of AA ILs for bioelectrochemical applications, such as biosensors and biofuel cells, is further enhanced by their ability to improve enzyme stability and facilitate electron transfer. In addition, AA ILs allow precise control of the deposition of metals and alloys, enabling the production of nanostructured or smooth films. Their complex abilities play a key role in optimizing deposition processes.  
Certain AA ILs also exhibit significant anticorrosion properties. For example, 1-cyanomethyl-3-vinylimidazolium derivatives such as [CyVIm][Trp], [CyVIm][His], and [CyVIm][Pro] effectively inhibit the corrosion of mild steel in neutral media [284], while [Ch][Phe] prevent the corrosion of mild steel in 1 M HCl [285]. Similarly, [Omim][Pro] acts as an effective anticorrosive, protecting mild steel in 0.5 M H\({}_{2}\)SO\({}_{4}\) and inhibiting copper corrosion in 3.5% NaCl solution by over 90% [286; 287]. Similarly, [Bmim][Lys] has been shown to inhibit the corrosion of carbon steel in 5% H\({}_{2}\)SO\({}_{4}\)[288].