Researchers have developed an innovative electrochemical biosensor that utilizes MXene nanosheets functionalized with specific antibodies to enable rapid vitamin D detection. Published in Communications Materials, this breakthrough aims to enhance point-of-care testing and improve accessibility to vitamin D monitoring.
Study: Antibody-functionalized MXene-based electrochemical biosensor for point-of-care detection of vitamin D deficiency. Image Credit: Aria Armoko/Shutterstock.com
Background
Vitamin D is essential for various physiological functions, and its deficiency is linked to severe health conditions. Accurate monitoring is crucial for preventing related health issues, especially in remote or underserved areas. However, current diagnostic methods require sophisticated laboratory equipment and skilled personnel, delaying timely patient care. This underscores the need for biosensors that are cost-effective, efficient, user-friendly, and capable of delivering reliable results in decentralized settings.
MXenes—two-dimensional transition metal carbides and nitrides—have gained attention in biosensing due to their excellent electrical conductivity, tunable surface properties, and compatibility with biological systems. Despite their promise, previous MXene-based biosensors have not been extensively explored for vitamin D detection, making this study a significant step forward.
The Study
The research focuses on the synthesis of Ti3C2Tx MXene nanosheets through a selective etching process of the MAX phase precursor material, resulting in an accordion-like structure. To enable covalent antibody attachment, the MXene surface was modified with polyethyleneimine (PEI), introducing amine functionalities that allow anti-vitamin D antibodies to bind via glutaraldehyde chemistry.
The study details the preparation process, including precise mixing ratios and conditions for optimal functionalization. Once prepared, the biosensor underwent electrochemical characterization to assess its sensitivity and specificity in detecting vitamin D. Techniques such as cyclic voltammetry (CV) and differential pulse voltammetry (DPV) were used, with phosphate-buffered saline (PBS) serving as the electrolyte.
Peak currents were analyzed across various vitamin D concentrations to determine sensitivity and specificity. Different scan rates helped assess the kinetics and diffusion mechanisms governing electrochemical reactions at the sensor’s interface. The detection limit and dynamic range were evaluated, covering clinically relevant vitamin D levels from deficiency (0.1 ng mL−1) to potential toxicity (500 ng mL−1). Control experiments ensured reliability and reproducibility across multiple sensor units.
Results and Discussion
The MXene-based biosensor demonstrated an impressive limit of detection of 1 pg mL−1—far surpassing existing technologies and meeting clinical standards for vitamin D detection. Its dynamic range effectively covers the full spectrum of vitamin D levels, making it highly relevant for medical assessments. Moreover, the sensor exhibited excellent specificity, with minimal interference from non-target biomolecules, ensuring accurate vitamin D detection in complex biological samples such as human serum.
Statistical analyses confirmed the biosensor’s robustness, with consistent results across multiple replicates and minor deviations, reinforcing its clinical potential. Tests with spiked serum samples further validated the sensor’s reliability in detecting vitamin D despite potential challenges posed by biological matrices. While surface biofouling was identified as a potential limitation, researchers are optimistic about future enhancements to address this issue.
Conclusion
This MXene-based electrochemical biosensor represents a significant advancement in point-of-care vitamin D detection. By leveraging the unique properties of functionalized MXenes, it achieves clinically relevant sensitivity and specificity without requiring additional amplification techniques or complex materials. The study not only underscores MXenes' potential in biosensing but also lays the foundation for future innovations in medical diagnostics, particularly in addressing nutrient deficiencies.
Rapid, sensitive, and cost-effective diagnostic tools like this biosensor could greatly improve patient care, especially in regions with limited access to traditional diagnostic facilities. Future research will focus on enhancing durability and minimizing biofouling to expand its applicability in diverse clinical settings. Integrating such technologies into healthcare systems could lead to more accessible health monitoring and improved public health outcomes worldwide.
Journal Reference
Barman S.C., Jin Y., et al. (2025). Antibody-functionalized MXene-based electrochemical biosensor for point-of-care detection of vitamin D deficiency. Communications Materials 6, 31. DOI: 10.1038/s43246-025-00756-9, https://www.nature.com/articles/s43246-025-00756-9