Electrochemical Detection Methods for Amino Acids in Biological Samples

Electrochemical approaches have become central to the quantitative analysis of amino acids in complex biological matrices. By measuring current or potential changes associated with redox reactions, these methods offer rapid, sensitive and label-free detection. Fundamental techniques include cyclic voltammetry, differential pulse voltammetry and amperometry, often performed on carbon-based electrodes such as glassy carbon or screen-printed platforms. Surface modifications with nanomaterials—graphene, metal nanoparticles, conducting polymers or molecularly imprinted films—enhance electron transfer, improve selectivity and lower detection limits. Strategies exploiting specific molecular recognition elements or electrocatalytic surfaces enable discrimination of structurally similar amino acids and real-time monitoring in matrices ranging from plasma to food extracts. The global significance spans clinical diagnostics, nutritional monitoring and environmental screening. Remaining challenges include minimising interference from co-existing biomolecules, ensuring reproducibility across sensor batches and integrating devices into portable or point-of-care formats. Recent advances focus on multiplexed arrays, hybrid nanocomposites and microfluidic integration to deliver highly selective, robust and user-friendly platforms for amino acid profiling in routine and decentralised settings.

Research from Nature Portfolio

Recent developments have demonstrated the feasibility of transforming electronic waste into high-performance sensors. One study converted graphite rods from spent batteries into electrodes for the detection of L-tryptophan in buffered solutions. Using both differential pulse and cyclic voltammetry, the sensor achieved a linear response over the micromolar range and a detection limit of under 2 µM. Optimisation of pH and scan parameters revealed a two-electron, two-proton oxidation mechanism controlled by both adsorption and diffusion. The repurposed graphite electrode successfully quantified L-tryptophan in milk and juice samples, illustrating a cost-effective, environmentally sustainable route to disposable biosensors.

Electrochemical Detection Methods for Amino Acids in Biological Samples publication trend

The graph below shows the total number of articles in electrochemical detection methods for amino acids in biological samples across all publications each year (not limited to Nature Index journals).

Technical terms

Cyclic voltammetry (CV): A technique measuring current response as potential is swept cyclically, used to characterise redox behaviour of analytes and electrode surfaces.

Differential pulse voltammetry (DPV): A pulse-based voltammetric method that enhances sensitivity and resolution by superimposing potential pulses on a linear sweep.

Screen-printed carbon electrode (SPCE): A mass-producible planar electrode fabricated by depositing carbon ink onto substrates, enabling low-cost, disposable analyses.

Glassy carbon electrode (GCE): A solid, highly conductive carbon electrode with a smooth surface, widely used for fundamental electrochemical studies.

Molecularly imprinted polymer (MIP): A synthetic material with tailored cavities that selectively bind target molecules, enhancing sensor selectivity.

Electrocatalytic activity: The ability of a material to catalyse electron-transfer reactions, thereby lowering analyte oxidation or reduction overpotentials and improving sensitivity.

References

1. C-undecylcalix[4]resorcinarene Langmuir–Blodgett/Porous Reduced Graphene Oxide Composite Film as a Electrochemical Sensor for the Determination of Tryptophan. Biosensors (2023).
2. Application of electrochemical sensor modified by SBA-15 /Fe3O4/polyaniline nanocomposite for determination of tyrosine in milk samples. Sensing and Bio-Sensing Research (2023).
3. Electrochemical determination of L-tryptophan in food samples on graphite electrode prepared from waste batteries. Scientific Reports (2022).
4. A Review of Sensors and Biosensors Modified with Conducting Polymers and Molecularly Imprinted Polymers Used in Electrochemical Detection of Amino Acids: Phenylalanine, Tyrosine, and Tryptophan. International Journal of Molecular Sciences (2022).