Gold nanoparticle amplification combined with quartz crystal microbalance DNA based biosensor for detection of mycobacterium tuberculosis

Abstract

Tuberculosis is among the top ten causes of global mortality and morbidity, constitutes an important public health problem in Thailand. This study demonstrates a rapid and sensitive quartz crystal microbalance (QCM) biosensor combined with gold nanoparticle amplification for diagnosis Mycobacterium tuberculosis. The functionalized gold electrode of the quartz crystal was immobilized using the specific thiol modified oligonucleotide probe. The sensitivity was also improved by using gold nanoparticle as mass enhancement at 3' end of DNA target sequence. The target IS6110 amplified DNA was hybridized to a probe for 5 min after application. DNA hybridization was indicated by resulted in frequency changes of the QCM. The QCM could clearly identify the data indicated that QCM could detect serial dilution of M. tuberculosis DNA limited as 5 pg of genomic DNA. The technique showed a significant specificity since no cross-hybridization with other mycobacteria was found. In testing in direct clinical sputum samples, the sensitivity of QCM was 100 %, and the specificity was 100% by comparison with culture. The label free QCM was successfully developed with high sensitivity, specificity, low cost and convenience, this technique may prove to be a powerful tool for an early diagnosis of M. tuberculosis. © 2012 IFSA.