# Biosensor-Based Platforms for the Detection and Screening of Mycobacterium leprae Infection

## TL;DR

Biosensors offer promising new tools for faster and more accurate leprosy diagnosis, especially in resource-limited areas.

## Contribution

A comprehensive review of biosensor-based platforms for leprosy detection, highlighting recent innovations and challenges.

## Key findings

- Biosensor platforms can achieve diagnostic accuracies above 90% for leprosy detection.
- Some biosensors can differentiate paucibacillary from multibacillary leprosy cases.
- Challenges include affordability, robustness, and lack of large-scale validation for clinical use.

## Abstract

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.