Simple and promising paper-based electrochemical platform for serological detection of American tegumentary leishmaniasis

BACKGROUND

American tegumentary leishmaniasis (ATL) is an endemic neglected tropical disease (NTD), its conventional treatment is toxic, slow, and invasive. Rapid diagnosis is crucial for the clinical management of suspected patients, so the development and use of low-cost, miniaturised and portable devices could be the key.

OBJECTIVES

This work aimed to develop a simple paper-based electrochemical platform for the serological detection of ATL.

METHODS

Platform was fabricated in Whatman N°1 paper, contains a hydrophobic zone generated by wax printing, two pencil graphite electrodes, and uses specific crude extracts (CA) antigens for ATL immuno-determination. The platform performance was analysed by measuring the relative impedance change for different antigen-antibody combinations. Then, 10 serum human samples previously diagnosed by the gold standard (five positive ATL cases and five non-ATL cases) were evaluated.

FINDINGS

The platform presented a linear response for the charge transfer resistance (ΔRct) and the interface reactance (ΔXc). Also, optimal working conditions were established (1/60 serum dilution and 180 µg/mL CA concentration). Then, the platform permits to distinguish between ATL and non-ATL (p < 0.05) human serum samples.

MAIN CONCLUSIONS

Our platform could allow the diagnosis, management, and monitoring of leishmaniasis while being an extremely simple and environmentally friendly technology.

Key words:
leishmaniasis; electrochemistry; graphite electrodes; paper-based; impedance; neglected disease; immunosensor