DNA-Mediated Au-Au Dimer-Based Surface Plasmon Coupling Electrochemiluminescence Sensor for BRCA1 Gene Detection

Area of Science:

• Nanotechnology
• Biosensing
• Electrochemistry

Background:

• Surface plasmon coupling electrochemiluminescence (SPC-ECL) offers high sensitivity for biosensing.
• Gold nanoparticles (Au NPs) are widely used due to their unique optical properties.
• Developing precise methods for detecting cancer biomarkers is crucial for early diagnosis.

Purpose of the Study:

• To construct a DNA-mediated Au-Au dimer-based SPC-ECL sensor.
• To investigate the effect of Au-Au dimers on electrochemiluminescence (ECL) signal enhancement.
• To develop a sensitive biosensor for detecting breast cancer susceptibility gene 1 (BRCA1).

Main Methods:

• Fabrication of Au-Au dimers using DNA scaffolds to connect two Au NPs.
• Utilizing graphite phase carbon nitride quantum dots (GCN QDs) as ECL emitters.
• Investigating the relationship between dimer gap distance and ECL signal amplification.

Main Results:

• Au-Au dimers significantly enhanced the ECL signal of GCN QDs via the hot spot effect.
• Maximum ECL signal enhancement of fourfold was achieved with a 2 nm dimer gap.
• The biosensor demonstrated high sensitivity for BRCA1 gene detection, with a limit of detection of 0.83 fM over a range of 1 fM to 1 nM.

Conclusions:

• The developed DNA-mediated Au-Au dimer SPC-ECL sensor provides an effective amplification strategy.
• This sensing mode enables precise and sensitive detection of BRCA1 genes.
• The study presents a promising platform for breast cancer diagnosis and prognosis.