Smart polymeric nanoparticles based immunodiagnostic platform and biosensor for Leptospira detection

Résumé :

The objective of this thesis was to develop a detection tool for leptospiral bacteria capable of
detecting them in various samples, such as human urine and blood, as well as water and soil from
the environment. The development of a rapid leptospirosis detection method, based on the
principle of latex particle agglutination, involved the preparation of polystyrene latex sensitized
by adsorption of anti-leptospira antibodies. This method, based on visual observation,
demonstrated good sensitivity and specificity for the detection of leptospira in environmental
water samples. Additionally, to increase sensitivity, an electrochemical sensor based on the use
of a specific oligonucleotide sequence was employed to detect leptospiral DNA in artificial urine
samples. The developed sensor showed very good sensitivity, indicating a detection limit below
the attomole (aM) level and no cross-reactions with other bacteria contaminating the urine. This
thesis proposes detection methods ranging from simple macroscopic detection to the use of an
electrochemical sensor for sensitive and specific detection.