Three-Dimensional DNA Hydrogel Mediated Dual-Mode Sensing Method for Quantification of Epithelial Cell Adhesion...

Area of Science:

• Biomedical Engineering
• Analytical Chemistry
• Nanotechnology

Background:

• Monitoring protein biomarkers like Epithelial cell adhesion molecule (EpCAM) in biological fluids is crucial for disease diagnosis.
• Existing methods for EpCAM quantification face challenges due to expression variability, soluble forms, and matrix effects.

Purpose of the Study:

• To develop a sensitive and reliable dual-mode sensing method for quantifying trace EpCAM in biological fluids.
• To establish a practical quantification strategy for EpCAM to aid in early disease diagnosis and health management.

Main Methods:

• A surface-enhanced Raman scattering (SERS)-fluorescence (FL) dual-mode sensing method was developed using bimetallic Au@Ag nanoparticles and nitrogen-doped quantum dots encapsulated DNA hydrogel hybrid with graphene oxide (Au@Ag-NQDs/GO).
• The method utilizes a DNA hydrogel with an aptamer DNA (AptDNA) linker that disassembles upon EpCAM interaction, triggering 'on-off' SERS and 'off-on' FL signals for simultaneous quantification.
• The sensing platform was tested for sensitivity, stability, and specificity using various biological fluid samples including cancer cell lysate, serum, and urine.

Main Results:

• The dual-mode method achieved high sensitivity and stability for EpCAM quantification in the range of 0.5-60.0 pg/mL.
• Limits of detection (LODs) for SERS and FL were as low as 0.17 pg/mL and 0.35 pg/mL, respectively.
• Satisfactory specificity and recoveries (RSDs 2.8-6.3%) were demonstrated in real biological samples.

Conclusions:

• The developed SERS-FL sensing method provides a sensitive, reliable, and practical approach for quantifying trace EpCAM in diverse biological fluids.
• This technique holds significant potential for improving early disease diagnosis and advancing health management strategies.