Response surface methodology optimized electrochemical DNA biosensor based on HAPNPTs/PPY/MWCNTs nanocomposite for...

Area of Science:

• Biosensor technology
• Nanomaterials in diagnostics
• Molecular detection of infectious diseases

Background:

• Rapid diagnosis of tuberculosis (TB) is crucial for effective treatment and prognosis.
• Current detection methods for Mycobacterium tuberculosis (M.tb) can be time-consuming.
• There is a need for sensitive, specific, and low-cost diagnostic tools for M.tb.

Purpose of the Study:

• To develop a rapid, PCR-free DNA biosensor for the detection of M.tb complex.
• To achieve highly sensitive and specific recognition of M.tb DNA.
• To optimize biosensor performance using statistical design methods.

Main Methods:

• Fabrication of a DNA biosensor using multi-walled carbon nanotubes (MWCNTs), polypyrrole (PPy), and hydroxyapatite nanoparticles (HAPNPs) on a glassy carbon electrode (GCE).
• Covalent attachment of M.tb ssDNA probes to the modified electrode surface.
• Detection of M.tb DNA hybridization via electrochemical signals of Methylene Blue using differential pulse voltammetry (DPV).
• Optimization of biosensor conditions using Plackett-Burman (PB) screening design and response surface method (RSM) with central composite design (CCD).

Main Results:

• The developed DNA biosensor demonstrated high sensitivity and specificity for M.tb detection.
• A wide linear detection range from 0.25 to 200.0 nM was achieved.
• A low limit of detection (LOD) of 0.141 nM was obtained.
• Successful application in detecting M.tb DNA extracted from clinical sputum samples.

Conclusions:

• The developed MWCNTs/PPy/HAPNPs-based DNA biosensor provides a rapid, sensitive, and cost-effective platform for M.tb detection.
• The integration of PB and RSM statistical designs enabled efficient optimization of biosensor performance.
• This biosensor shows significant potential for practical clinical diagnosis of tuberculosis.