Biosensor-Based Platforms for the Detection and Screening of <i>Mycobacterium leprae</i> Infection

Leprosy remains an important neglected tropical disease with about 200,000 new cases detected annually worldwide. Although the disease is highly responsive to treatment, a timely and accurate diagnosis continues to be a critical barrier to disease control. Traditional diagnostic methods, including PCR, bacilloscopy, histopathology, and serology, are hindered by limited sensitivity, procedural complexity, and restricted accessibility in resource-constrained settings. This review summarizes studies from the past decade on biosensor-based strategies for leprosy diagnosis. Biosensor platforms for leprosy include electrochemical, piezoelectric, and optical systems, with recent innovations encompassing immunosensors, biomimetic, and DNA-based approaches, some achieving diagnostic accuracies above 90%. These platforms employ different bioreceptors such as conjugated peptides, DNA probes, and molecularly imprinted polymers. Certain platforms can also differentiate paucibacillary from multibacillary cases, addressing a critical limitation of the current methods. These capabilities highlight the potential of biosensors as powerful tools for point-of-care testing. However, clinical translation is constrained by challenges such as affordability, robustness under field conditions, and the lack of large-scale validation studies. Additional operational barriers, including regulatory approval, supply chain logistics, and user training, must also be addressed. Future progress will depend on multidisciplinary strategies, integrating novel biomarker discovery as recognition elements and exploring detection systems previously used for other mycobacterial and infectious diseases. Large multicenter trials and user-centered design approaches are essential for clinical implementation. By overcoming these challenges, biosensors have the potential to redefine leprosy diagnostics, enabling earlier detection and improved surveillance, and accelerating progress toward global elimination goals.