Droplet-based microscale colorimetric biosensor for multiplexed DNA analysis via a graphene nanoprobe

Area of Science:

• Microfluidics
• Biosensing
• Nanotechnology

Background:

• Droplet-based microfluidic systems require simple and cost-effective DNA detection strategies.
• Multiplexed DNA analysis is crucial for various biological and diagnostic applications.

Purpose of the Study:

• To develop a droplet-based biosensor for simultaneous, sensitive, and inexpensive multiplexed DNA detection.
• To utilize a graphene nanoprobe and fluorescence-based colorimetric method for DNA analysis within microfluidic droplets.

Main Methods:

• Development of a droplet-based biosensor integrating droplet manipulation techniques (size adjustment, fusion, trapping).
• Utilized graphene oxide (GO) as a nanoprobe for fluorescence quenching of FAM and ROX labeled DNA probes.
• Employed a fluorescence-based colorimetric method for detecting target DNA presence through changes in fluorescence intensity.

Main Results:

• Achieved accurate and precise droplet manipulation for biosensing.
• Demonstrated a colorimetric shift from dark to bright upon target DNA hybridization due to fluorescence recovery.
• Exhibited quantitative capability for simultaneous detection of two DNA targets with detection limits of 9.46 and 9.67×10⁻⁸ M.

Conclusions:

• The developed colorimetric droplet biosensor is a promising tool for high-throughput DNA analysis with low reagent consumption.
• Integration of graphene nanoprobes and droplet technology advances the field of biosensing.
• The strategy provides a simple, inexpensive, and sensitive platform for multiplexed DNA detection.