Optimized DNA-based bioassay for Leptospira interrogans detection: a novel platform for leptospirosis diagnosis

Abstract

An optimized DNA-based bioassay for Leptospira interrogans detection has been developed. Electrochemical studies of the developed biosensor were done using cyclic voltammetry (CV) and differential pulse voltammetry (DPV). Surface characterization of the biosensor was done using scanning electron microscopy (SEM). The biosensor showed specificity to L. interrogans as determined by specificity studies. The sensitivity of the biosensor was 264.5 µA/cm 2 /ng and lower limit of detection (LOD) was 0.015 ng/6 µl using CV. The biosensor was also validated with serum samples spiked with singlestranded leptospiral DNA. The developed biosensor also showed good stability for a period of 6 months at 4 °C as shown by the DPV analysis. Research highlightsThe developed DNA-based bioassay is the first report on biosensor-based leptospirosis diagnosis. The developed bioassay is a DNA-based amperometric biosensor specific to L. interrogans causing leptospirosis. The biosensor has a sensitivity of 264.5 µA/cm 2 /ng and a lower limit of detection (LOD) of 0.015 ng/6µl. The biosensor was stable for 6 months with only 13% loss in DPV peak current.

Leptospira interrogans Outer Membrane Protein-Based Nanohybrid Sensor for the Diagnosis of Leptospirosis

“…The developed assay was found to be more specific and sensitive than the previously reported biosensors [ 23 , 27 ] developed for detecting leptospirosis. The performance of the electrochemical DNA biosensor depends upon the surface area and conductivity of the working electrode surface.…”

“…It can create a point-of-care diagnostics facility even outside the laboratory settings and can be a replacement of the current diagnosis methods that require sophisticated instrument facilities and experts to carry out the tests [ 22 ]. In the way of such advancements, a step has already been taken by Nagraik et al by developing an amperometric DNA sensor for the diagnosis of leptospirosis by targeting the highly conserved LipL32 gene of L. interrogans as a genetic marker [ 23 ]. The sensor was reported with higher sensitivity, specificity, and storage stability.…”

Molecular and serological diagnostic of leptospirosis: a review (2014–2020)

“…Moreover, the lipL32 gene was described in an optimized DNA-based bioassay for the detection of Leptospira interrogans, which used gold nanoparticle-embedded carboxylated multiwalled carbon nanotubes electrode (Nagraik et al, 2019).…”

Understanding of Colistin Usage in Food Animals and Available Detection Techniques: A Review

“…It is wellknown that there is dire need for improvement in colistin detection with high accuracy and specificity in animal food. Few bio-sensors have been developed for identifying food-related disorders, like the transglutaminase-based nano-sensor for the prognosis of the celiac disorder, as well as human pathogens, e.g., quick detection of Streptococcus pyogenes and Leptospirainterrogans [ 102 , 103 , 104 ]. New improvements and novel changes are required in techniques based on precision and specificity to fulfil the future demand for colistin detection and to develop novel biosensors for rapid identification of colistin in animal-based food.…”