Heterodimeric aptamer improves the limit of detection of sandwich ELASA and dot blot assay.

Heterodimerization, which is an amalgamation of discrete aptamers into a single functional module is a viable strategy to augment the binding strength of aptamers. In this study, we sought to derive several heterodimeric aptamers using the discrete aptamers, LepDapt-2a and LepDapt-5a prior to their binding evaluation against the target LipL32. We further integrated heterodimeric aptamer LepDapt-H1b as a detection aptamer into aptamer-based sandwich ELASA and dot blot assay for the detection of Leptospira, attaining a LOD of 4 and 10 CFU/mL for both assays, respectively, which are better compared to our previous study. Additionally, the LOQ acquired for sandwich ELASA assay was 11 CFU/mL. We have proven that heterodimerization has improved the performance of sandwich ELASA and dot blot assay, suggesting them to be applicable for the diagnostics of leptospirosis.