Innovative Chitosan–Molybdenum Disulfide Sensor: Highly Sensitive Dopamine Detection for Early Diagnosis of Neurological Disorders
Novel chitosan– MoS2-nanocomposites open new perspectives for the diagnosis of neurological diseases
Dopamine is one of the most important neurotransmitters in the human brain. Its imbalance is associated with neurological disorders such as Parkinson’s disease, schizophrenia, or Huntington’s disease.
Accurate and early detection of this neurotransmitter is therefore essential. A research team has now developed an innovative electrochemical sensor based on a hybrid material composed of chitosan and molybdenum disulfide (MoS2), offering excellent sensitivity and selectivity.
MoS2- and Chitosan: Synergy at the Nanoscale
MoS2 is a two-dimensional material with high electrical conductivity and pronounced catalytic activity - properties that make it ideally suited for use in electrochemical sensors. Combined with chitosan, a biocompatible polysaccharide, a nanocomposite is formed that combines the benefits of both components: high conductivity, large surface area, and biological compatibility.
The synthesis of the chitosan-MoS2 composite is achieved through a simple liquid-phase exfoliation process, in which MoS2 nanosheets are combined with a chitosan solution. The resulting hybrid materials are applied to commercial carbon electrodes and electrochemically characterized.
Top-Level Sensitivity and Selectivity
The sensor exhibits two linear response ranges for dopamine concentrations: 0-40 µM and 40-440 µM, with a detection limit as low as 0.8 µM. Compared to previous systems based solely on MoS2 or chitosan, the combination of both materials results in a significant performance boost. Additionally, the sensor demonstrates excellent selectivity against potentially interfering substances such as uric acid, glucose, or ascorbic acid - an essential advantage for real-world applications in biological samples like blood serum or saliva.
Finding the Optimal Composition
The study shows that a chitosan content of 50 % in the nanocomposite provides the best balance between electrical conductivity and stability. Higher chitosan concentrations tend to block active surface areas, thereby reducing sensitivity. In addition to optimizing the material composition, the electrode design was also systematically refined to maximize performance.
Ready for Real-World Applications
In tests with real serum and saliva samples, dopamine concentrations were determined with high accuracy - achieving recovery rates of 97.5 % and 105.8 %. The sensors proved to be reusable and reproducible, making them particularly attractive for clinical diagnostics and neurological research.
Conclusion
With the development of a cost-effective, stable, and selective sensor based on chitosan-MoS2 nanocomposites, this study paves the way for new biosensing applications. The combination of biocompatibility and electrochemical performance makes this sensor a promising tool in medical diagnostics - particularly for the early detection and monitoring of neurodegenerative diseases.
Sources
Wali, R.; Zribi, R.; Bressi, V.; Maalej, R.; Foti, A.; Gucciardi, P. G.; Cheikhrouhou-Koubaa, W.; Neri, G. Advanced 2D MoS₂–chitosan nanocomposites for ultra-sensitive and selective dopamine detection. Materials Advances, 2025. DOI: 10.1039/d5ma00133a
First published on 21st of August 2025
Revised on 21st of August 2025