RESUMO
Detecting and monitoring the pathogens with high selectivity and sensitivity is critical for public health. In the present study, we demonstrated a specific analytical strategy for sensitive detection of Leishmania infantum genome. The developed sensor utilized toluidine blue as a hybridization indicator and a Leishmania infantum-specific capture DNA sequence immobilized on a high-surface area gold nanostructure as an electrochemical transducer. The produced analytical response was based on the hybridization of the single-stranded DNA from the target with the immobilized DNA sequence at the electrode surface. The developed DNA sensor in this study was successfully employed to detect a synthetic Leishmania infantum target sequence in a wide concentration range from 1â¯×â¯10-18 to 1â¯×â¯10-10â¯molâ¯L-1 with a detection limit of 0.2â¯amolâ¯L-1 with the ability to discriminate the target sequence from mismatched sequences. Moreover, the designed DNA sensor showed a good reproducibility and stability during repeated regeneration and hybridization cycles. The DNA sensor could detect Leishmania infantum genome in a wide concentration range from 15 to 50â¯ng⯵L-1 with a detection limit of 29â¯ng⯵L-1. Furthermore, clinical trials confirmed the applicability of the developed DNA sensor for practical applications.