A ratiometric SERS aptasensor array for human DNA glycosylaseat single-cell sensitivity/resolution.

Area of Science:

• Biochemistry
• Genomics
• Nanotechnology

Background:

• Human 8-oxoguanine DNA glycosylase (hOGG1) is crucial for repairing 8-oxoguanine, maintaining genome stability.
• Accurate hOGG1 activity detection is vital for diagnosing and treating human diseases.
• Current methods for quantifying hOGG1 activity suffer from poor reproducibility and portability.

Purpose of the Study:

• To develop a reproducible and portable point-of-care testing method for quantifying hOGG1 activity.
• To enhance the sensitivity and reliability of hOGG1 detection using a ratiometric approach.
• To provide a flexible tool for clinical diagnostics, biochemical analysis, and drug discovery.

Main Methods:

• Fabrication of a reproducible, uniform, and stable plasmonic multi-microarray reaction cell using gold nanoparticles (AuNPs).
• Development of a ratiometric surface-enhanced Raman spectroscopy (SERS) assay utilizing two Raman-labeled probes: a Cy3-labeled aptamer as an internal standard and a Rox-labeled aptamer as a signal probe.
• Quantitative detection of hOGG1 activity by measuring the intensity ratio between Cy3 and Rox SERS signals.

Main Results:

• The ratiometric SERS method demonstrated high sensitivity, portability, and repeatability.
• The ratio of Cy3 to Rox SERS intensity showed a linear correlation with hOGG1 activity over a range of 5 × 10⁻⁵ to 5 × 10⁻³ U/mL.
• A limit of detection of 3.3 × 10⁻⁵ U/mL was achieved, significantly improving upon existing methods.

Conclusions:

• The proposed ratiometric array-based SERS method provides a robust and reliable platform for hOGG1 activity detection.
• This technology overcomes the limitations of existing methods, offering improved sensitivity and portability for point-of-care applications.
• The method is adaptable for inhibitor screening, monitoring cellular hOGG1 activity, and advancing clinical diagnostics and drug discovery.