Rapid detection of Mycobacterium tuberculosis based on aptamer modified surface-enhanced Raman scattering biosensors

Area of Science:

• Biomedical Engineering
• Analytical Chemistry
• Infectious Disease Diagnostics

Background:

• Tuberculosis (TB) remains a significant global health threat, causing millions of deaths annually.
• Traditional TB diagnostic methods suffer from low sensitivity, specificity, and high costs.
• MPT64 antigen is a specific biomarker for Mycobacterium tuberculosis (Mtb) complex.

Purpose of the Study:

• To develop an innovative and efficient strategy for Mtb detection in serum.
• To create a dual aptamer-modified surface-enhanced Raman scattering (SERS) biosensor for MPT64 detection.
• To evaluate the sensitivity, specificity, and quantitative capabilities of the proposed biosensor.

Main Methods:

• Fabrication of SERS probes using gold-core silver-shell nanoparticles and NBA Raman reporter molecules functionalized with MPT64 aptamer A.
• Preparation of magnetic bead-based capturing probes modified with MPT64 aptamer B.
• Development of a one-step substrate capture and detection system for MPT64 in human serum.

Main Results:

• The aptamer-SERS biosensor demonstrated a good linear relationship between MPT64 concentration and Raman intensity (R² = 0.9963) within a wide dynamic range.
• Achieved a low detection limit of 20 fg/mL for MPT64.
• In human serum samples, the biosensor exhibited 100% sensitivity and specificity for tuberculosis detection.

Conclusions:

• The developed aptamer-SERS biosensor provides a reliable and efficient method for quantitative tuberculosis diagnosis.
• This innovative approach overcomes the limitations of traditional TB diagnostic techniques.
• The biosensor shows great potential for clinical application in rapid and accurate TB detection.