Aptamer-engineered gold nanorod driven an absorbance enhanced strategy for sensitive biomacromolecule profiling

Area of Science:

• Nanotechnology
• Biochemistry
• Analytical Chemistry

Background:

• Gold nanorods (AuNRs) offer designable plasmonic biosensors for biomacromolecule quantification.
• Existing AuNR biosensors often require target-induced aggregation or etching, limiting detection of low concentrations.
• Detecting biomacromolecules at extremely low concentrations without aggregation remains a challenge.

Purpose of the Study:

• To develop a universal absorbance enhancement strategy for sensitive biomacromolecule detection using engineered AuNRs.
• To overcome the limitations of aggregation-dependent detection methods for low-concentration targets.
• To demonstrate a versatile platform for detecting various biomacromolecules in complex biological fluids.

Main Methods:

• Assembly of aptamers onto AuNRs to create an aptamer-engineered AuNR (Apts/AuNRs) biosensor.
• Utilizing proximity-dependent ligation to form a closed-loop conformation upon target binding.
• Measuring absorbance enhancement at the plasmonic peak of AuNRs as an indicator of target presence.

Main Results:

• The Apts/AuNRs biosensor demonstrated a gradual absorbance enhancement with increasing protein concentration, without inducing AuNR aggregation or etching.
• Achieved picomole-level detection limit for cytochrome C, outperforming gold nanoparticles (AuNPs) based sensors.
• Successfully analyzed telomerase activity in nerve cell lysate, with results comparable to ELISA kits and good recovery rates.

Conclusions:

• The proposed absorbance enhanced strategy provides a sensitive, selective, and universal method for biomacromolecule detection.
• This approach expands the utility of AuNRs' plasmonic properties for analyzing challenging low-concentration targets.
• The Apts/AuNRs biosensor offers a simple and credible platform for biomacromolecule quantification in complex biofluids.