Colorimetric DNA based biosensor combined with loop-mediated isothermal amplification for detection of Mycobacterium tuberculosis by using gold nanoprobe aggregation

Abstract

Tuberculosis is a persistent problem in the developing world and the biggest cause of mortality. Loop-mediated isothermal amplification (LAMP) allows DNA to be amplified rapidly at a constant temperature. Here, a LAMP method was combined with a gold nanoparticle (AuNPs) probes to detect IS6110 of M. tuberculosis rapidly, and specifically. The reaction amplified DNA and hybridized to thiol modified oligonucleotide probe for 5 min was detected at AuNPs color change 5 min after application. Excluding for the step of DNA extraction, test results could be generated approximately within 1 h. Furthermore, the data indicated that LAMP-AuNPs could detect serial dilution of M. tuberculosis DNA limited as 5 pg of genomic DNA. According to the sensitivity, specificity, less time consuming, low cost and convenience, this technique may prove to be a powerful tool for the early diagnosis of M. tuberculosis. © 2013 IFSA.