RCA-Based Biosensor for Electrical and Colorimetric Detection of Pathogen DNA

Area of Science:

• Biotechnology
• Biosensor Technology
• Molecular Diagnostics

Background:

• Pathogen detection is crucial for disease diagnosis and prevention.
• Existing methods for pathogen detection require improvement in sensitivity and speed.
• Development of rapid and reliable biosensors is essential for public health.

Purpose of the Study:

• To synthesize a novel rolling circle amplification (RCA)-based biosensor for pathogen DNA detection.
• To enable pathogen DNA detection using two distinct analytical modes within a single system.
• To provide a versatile platform for monitoring pathogenic DNA.

Main Methods:

• Rolling circle amplification (RCA) was employed for DNA polymerization.
• A biosensor utilizing gold (Au) electrodes was functionalized with DNA.
• Changes in electrode surface structure and gap were monitored.
• Hydrogen tetrachloroaurate (HAuCl4) was used to enhance electrical conductivity.
• Colorimetric changes (yellow to orange-red) were observed for visual detection.

Main Results:

• The RCA-based biosensor successfully detected target pathogen DNA.
• Continuous polymerization during RCA altered the Au electrode surface and gap.
• An electrical signal was generated upon HAuCl4 addition, indicating DNA presence.
• A visible color change confirmed the detection of target DNA.
• The biosensor demonstrated dual-mode detection capabilities.

Conclusions:

• The developed RCA-based biosensor provides a sensitive and efficient method for pathogen DNA detection.
• The dual analytical modes (electrical and colorimetric) offer flexibility and reliability.
• This platform presents a significant advancement in molecular diagnostics for pathogen monitoring.