Reduced graphene oxide-based absorbance biosensors for detecting Escherichia coli DNA

Area of Science:

• Materials Science
• Biotechnology
• Analytical Chemistry

Background:

• Escherichia coli (E. coli) poses significant risks to food safety, water quality, and public health.
• Effective and sensitive detection methods for E. coli are crucial for monitoring and control.
• Current detection methods may lack the sensitivity or specificity required for rapid diagnostics.

Purpose of the Study:

• To develop and characterize a novel biosensor for the sensitive and specific detection of E. coli DNA.
• To utilize functionalized reduced graphene oxide (rGO) as a platform for DNA biosensing.
• To evaluate the performance, including limit of detection and selectivity, of the developed biosensor.

Main Methods:

• Reduced graphene oxide (rGO) was synthesized using a modified Hummers' method and hydrothermal reduction.
• Characterization of rGO was performed using Fourier-transform infrared spectroscopy, scanning electron microscopy, and X-ray diffraction.
• A biosensor was constructed by immobilizing amino-modified probe DNA specific to E. coli on functionalized rGO, detecting DNA via absorbance changes.

Main Results:

• The rGO-based biosensor demonstrated sensitive detection of E. coli DNA in the range of 0-476.19 fM.
• A limit of detection (LOD) of 80.28 fM was achieved, indicating high sensitivity.
• The biosensor exhibited excellent selectivity, distinguishing E. coli from other bacterial species like Bacillus subtilis and Staphylococcus.

Conclusions:

• The developed rGO-based biosensor offers a promising platform for rapid, sensitive, and specific detection of E. coli DNA.
• This technology has potential applications in pathogen monitoring, clinical diagnostics, and environmental analysis.
• The study highlights the utility of functionalized rGO in advancing DNA biosensing technologies.