Nanofabricated versatile electrochemical sensor for Leptospira interrogans detection

• Published in: Journal of bioscience and bioengineering Vol. 129; no. 4; pp. 441 - 446
• Main Authors: Nagraik, Rupak, Kaushal, Ankur, Gupta, Shagun, Sethi, Sunil, Sharma, Avinash, Kumar, Dinesh
• Format: Journal Article
• Language: English
• Published: Japan Elsevier B.V 01.04.2020
• Subjects: carbon nanotubes; carboxylation; complementary DNA; Electrochemical sensor; electrochemistry; electrodes; genes; graphene; Graphene quantum dots; Leptospira interrogans; LipL32 gene; methylene blue; nanogold; quantum dots; Raman spectroscopy; scanning electron microscopy; sensors (equipment); single-stranded DNA; Specificity; storage temperature; Specificity; Leptospira interrogans; LipL32 gene; Electrochemical sensor; Graphene quantum dots
• ISSN: 1389-1723; 1347-4421; 1347-4421
• DOI: 10.1016/j.jbiosc.2019.11.003

In this report, a LipL32 gene based nanofabricated electrochemical sensor for the detection of Leptospira interrogans has been developed using carboxylated multiwalled carbon nanotubes with gold nanoparticles (c-MWCNTs/nanoAu) electrode and graphene quantum dots (GQDs). The c-MWCNTs/nanoAu electrode was linked to GQDs using 4-aminothiophenol (ATP). The surface modifications on the electrode surface were delineated using Raman spectroscopy and field emission scanning electron microscopy (FE-SEM). 5′-Amino (NH2) labeled single stranded DNA (ssDNA) probe was immobilized on the surface of c-MWCNTs/nanoAu/ATP/GQD composite electrode. The electrochemical changes of the developed sensor after hybridization with single stranded complementary DNA of L. interrogans were analyzed by differential pulse voltammetry (DPV) using 1 mM methylene blue. The sensor showed good linearity with complementary ssDNA concentration ranging from 0.37 to 12 ng/μl. The sensor exhibited high specificity to L. interrogans and showed good reproducibility when stored at 4°C. •This is the first report on GQD based sensor for the detection of Leptospira interrogans.•The developed sensor was characterized using Raman spectroscopy and FE-SEM.•Electrochemical analysis was done using DPV.•The sensor generated a good electrochemical response to ssDNA concentration of L. interrogans ranging from 0.37 to 12 ng/μl.