Tunable plasmonic colorimetric assay with inverse sensitivity for extracellular DNA quantification

Area of Science:

• Environmental Science
• Nanotechnology
• Molecular Biology

Background:

• Extracellular DNA (eDNA) is crucial for characterizing microbial communities in various environments.
• Current methods for eDNA detection may lack the sensitivity or dynamic range required for comprehensive environmental monitoring.

Purpose of the Study:

• To develop a gold nanorod (AuNR)-based colorimetric assay for sensitive and tunable detection of extracellular DNA (eDNA).
• To optimize assay parameters for effective quantification of environmental eDNA.

Main Methods:

• Development of a colorimetric assay utilizing gold nanorods (AuNRs).
• Investigation of key parameters influencing assay performance: AuNR aspect ratio, DNA length, and DNA structure.
• Evaluation of assay sensitivity and dynamic range for eDNA detection.

Main Results:

• The developed AuNR-based assay exhibits inverse sensitivity, allowing for tunable detection ranges.
• Identification of critical parameters (AuNR aspect ratio, DNA length/structure) that enhance assay performance.
• The assay achieved detection levels suitable for quantifying environmental eDNA.

Conclusions:

• The novel AuNR colorimetric assay provides a versatile tool for environmental eDNA analysis.
• The assay's tunable dynamic range and sensitivity address limitations in current eDNA quantification methods.
• This approach facilitates more accurate characterization of microbial communities in soil and aquatic ecosystems.