Modified gold nanoparticle colorimetric probe-based biosensor coupled with allele-specific PCR for rapid detection of G944C mutation associated with isoniazid resistance

The emergence of multidrug-resistant (MDR) strains of Mycobacterium tuberculosis (MTB) makes tuberculosis (TB) difficult to control and treat. Therefore, rapid and reliable detection of MDR-TB within the community plays a significant role. The aim of this study was to investigate the use of modified gold nanoparticle (AuNP) colorimetric probe-based biosensor coupled with allele-specific PCR for the rapid detection of G944C mutation associated with isoniazid resistance in MTB. Based on the citrate reduction method, the AuNPs were synthesized and functionalized using thiol-modified oligonucleotides (AuNP-biosensor). The AuNP-biosensor method was compared to the gold standard in terms of analytical and clinical sensitivity and specificity, positive predictive value (PPV), negative predictive value (NPV), diagnostic odds ratio (DOR), and accuracy. The gold standard was defined as a positive result in sequencing. The AuNP-biosensor had 100% sensitivity and specificity for detection of G944C mutation. After allele-specific PCR amplification the results were carried out for