Colorimetric biosensing of targeted gene sequence using dual nanoparticle platforms

Area of Science:

• Nanotechnology
• Biosensing
• Molecular Biology

Background:

• Salmonella enterica is a significant foodborne pathogen.
• Accurate and rapid detection methods are crucial for public health.
• Existing methods may lack specificity or sensitivity.

Purpose of the Study:

• To develop a novel colorimetric biosensor for Salmonella enterica detection.
• To utilize a dual platform of gold nanoparticles and graphene oxide.
• To detect the presence of the invA gene specific to S. enterica.

Main Methods:

• Development of a dual platform biosensor using gold nanoparticles and graphene oxide.
• DNA hybridization assay for detecting the invA gene.
• Colorimetric analysis and spectrophotometry for signal detection.
• Specificity and sensitivity testing against various bacterial species and DNA concentrations.

Main Results:

• The biosensor exhibited a color change from pinkish-red to light purple upon detection of S. enterica.
• Spectrophotometry showed a wavelength shift from 525 nm to 600 nm with 1 μM DNA target.
• The biosensor demonstrated high specificity, detecting various S. enterica serovars without cross-reactivity.
• The limit of detection was determined to be as low as 1 nM of DNA target.

Conclusions:

• The developed colorimetric biosensor is effective for sensitive and specific detection of Salmonella enterica.
• The dual platform of gold nanoparticles and graphene oxide enhances detection capabilities.
• This biosensor offers a promising tool for rapid identification of S. enterica through DNA hybridization.