Electrochemical Detection of Melatonin in Biological Samples

Melatonin is a pivotal endogenous hormone regulating circadian rhythms and exhibiting neuroprotective, antioxidative and immunomodulatory properties. Accurate quantification of melatonin in complex biological matrices such as serum, urine and pharmaceutical formulations is essential for clinical diagnostics, sleep research and therapeutic monitoring. Electrochemical detection techniques offer rapid, sensitive and cost-effective approaches that can be miniaturised for point-of-care devices. The core methods include voltammetric and amperometric measurements, which transduce oxidation of melatonin at a modified electrode into measurable current responses. Key challenges lie in achieving low nanomolar detection limits amid interference from endogenous compounds such as ascorbic acid, dopamine and uric acid. Advances in electrode engineering have addressed these challenges by incorporating nanostructured materials—graphene derivatives, transition-metal dichalcogenides, carbon nanotubes, metal nanoparticles and host–guest supramolecular systems—that enhance surface area, electron transfer kinetics and selectivity. Photoelectrochemical strategies further exploit light-induced charge separation to boost sensitivity. Collectively, these innovations have delivered sensors with detection limits in the sub-micromolar to nanomolar range, high reproducibility and applicability to real biological samples. Ongoing efforts aim to integrate these sensors into wearable platforms and automated systems for longitudinal monitoring of melatonin profiles in health and disease.

Research from Nature Portfolio

Recent studies have reported an innovative sensor that harnesses a supramolecular complex between cucurbit[8]uril and two-dimensional MoS₂ nanosheets. The host–guest assembly enhances pre-concentration of melatonin at the electrode interface, while the high conductivity and catalytic edge sites of MoS₂ accelerate electron transfer. Detailed electrochemical impedance spectroscopy revealed efficient charge transfer during melatonin oxidation, and differential pulse voltammetry achieved a detection limit of 3.8 × 10⁻⁷ M. The sensor demonstrated recoveries between 90 % and 102 % in human urine, serum and pharmaceutical samples, underscoring its potential for practical analytical applications.

Electrochemical Detection of Melatonin in Biological Samples publication trend

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

Technical terms

Voltammetry: Electrochemical method measuring current as a function of applied potential to characterise redox processes.

Amperometry: Technique in which a constant potential is applied and the resulting current due to oxidation or reduction is monitored over time.

Limit of detection: Lowest concentration of an analyte that can be reliably distinguished from background noise.

Nanocomposite: Hybrid material combining nanoparticles with a supporting matrix to enhance mechanical, electrical or catalytic properties.

Photoelectrochemical sensing: Analytical approach that uses light-driven charge separation at a photoactive electrode to amplify detection signals.

References

1. Ruthenium-Anchored Carbon Sphere-Customized Sensor for the Selective Amperometric Detection of Melatonin. Biosensors (2023).
2. Electrochemical sensor based on the synergy between Cucurbit[8]uril and 2D-MoS2 for enhanced melatonin quantification. Scientific Reports (2023).
3. Carbon‐Nanotube Microelectrodes for Electrochemical Determination of Melatonin. Electroanalysis (2024).
4. Decoupling photonic and thermal contributions for photoelectrochemical sensing of melatonin via graphene oxide nanoribbons. Electrochemistry Communications (2024).