Dendritic Nanotip For Low-Cost Detection Of Mycobacterium Tuberculosis

Rapid diagnosis of tuberculosis, one of the most widely spread diseases on the globe today, has been critically demanded for over a century. One of the major challenges for screening Mycobacterium tuberculosis (MTB) is in low-cost detection of MTB. In this study, we present an electrical detection method of MTB cells using a dendritic nanotip composed of single-walled carbon nanotubes (SWCNTs) and Si micro- and nanowires. The novelty is in the direct measurement of electric current with a minimal capacitance effect on dendritic nanotip surface. Upon binding of target cells, a gating effect on the nanotip surface decreases the electric current, which is measured directly by a dendritic nanotip. The measurement resolution is aided by reduced interference of an electrical double layer effect, due to the dendritic nanostructure. Using the nanotip, BCG cells could be electrically detected within 15 minutes, which is validated by fluorescence detection. The sensitivity is 1000 cfu/ml for both methods. The presented tip sensor demonstrated the potential for rapid and low-cost detection of MTB.