Interdigitated Electrode Biosensor Based on Plasma-Deposited TiO₂ Nanoparticles for Detecting DNA.

Area of Science:

• Nanomaterials Science
• Biosensor Technology
• Medical Diagnostics

Background:

• Metal oxide nanoparticles are crucial for developing advanced medical diagnostic sensors.
• Titanium dioxide (TiO2) nanoparticles offer unique properties for bioelectronic applications.

Purpose of the Study:

• To fabricate and characterize a novel DNA biosensor using high-purity TiO2 nanoparticles.
• To detect the pathogenic bacterium *E. coli* O157:H7 using the developed DNA biosensor.
• To evaluate the biosensor's specificity and quantitative detection capabilities.

Main Methods:

• Synthesis of high-purity TiO2 nanoparticles via thermal plasma.
• Deposition of TiO2 NPs onto an interdigitated electrode, followed by surface activation with APTES and probe DNA immobilization.
• Structural and chemical characterization using TEM, XRD, XPS, SEM, and DLS.
• Detection of target DNA using a picoammeter to measure current changes.

Main Results:

• Successful fabrication of a DNA biosensor with TiO2 nanoparticle-modified electrodes.
• Quantitative detection of *E. coli* O157:H7 DNA based on electrical signal transduction.
• Demonstrated high specificity, distinguishing between complementary, non-complementary, and mismatched DNA sequences.

Conclusions:

• The developed TiO2 nanoparticle-based DNA biosensor is a promising tool for sensitive and specific detection of pathogenic bacteria.
• This approach offers a viable platform for advancing medical diagnostics through bioelectronic sensing.
• The biosensor's ability to convert DNA binding events into measurable electrical signals enables accurate quantification.