Portable immunosensor directly and rapidly detects Mycobacterium tuberculosis in sputum

Area of Science:

• Biomedical Engineering
• Infectious Disease Diagnostics
• Biosensor Technology

Background:

• Tuberculosis (TB) remains a significant global public health challenge.
• Current Mycobacterium tuberculosis (MTB) detection methods are often time-consuming, inflexible, and not suitable for field use.
• There is a critical need for rapid, portable, and efficient diagnostic tools for TB.

Purpose of the Study:

• To develop and characterize a portable immunosensor for the rapid detection of MTB in sputum.
• To optimize the immunosensor's performance through voltage control and interface characterization.
• To evaluate the sensor's specificity and its effectiveness in diagnosing TB from patient samples.

Main Methods:

• Fabrication and interface characterization (SEM, contact angle, fluorescence) of a portable immunosensor.
• Optimization of source and gate voltages using non-contact photoresponse measurements.
• Anti-interference testing with common proteins and validation using actual TB patient sputum samples in a double-blind experiment.

Main Results:

• The immunosensor demonstrated increased sensitivity with decreased source voltage and signal amplification (≥1.6x) with optimized gate voltage (0.1 V).
• Optimal detection conditions were determined at a source voltage of 0.3 V and gate voltage of 0.1 V.
• The sensor showed good specificity against common proteins and successfully distinguished TB sputum from healthy individuals in minutes, without preconditioning.

Conclusions:

• The developed portable immunosensor provides a rapid, specific, and efficient method for TB diagnosis.
• This technology offers a significant improvement over conventional culture-based methods, reducing detection time to minutes.
• The study presents a promising new strategy for point-of-care and portable diagnosis of tuberculosis.