Ultrasensitive detection of small biomolecules using aptamer-based molecular recognition and nanoparticle counting

Area of Science:

• Biotechnology
• Nanotechnology
• Analytical Chemistry

Background:

• Detecting small biomolecules is crucial for biological research and clinical diagnostics.
• Current antibody-based methods struggle with low concentrations of small biomolecules.
• There is a need for highly sensitive and high-throughput detection methods.

Purpose of the Study:

• To develop a new method for ultrasensitive detection of small biomolecules using nanoparticle counting.
• To overcome the limitations of existing antibody-based detection techniques.
• To demonstrate the method's feasibility and sensitivity using adenosine as a model.

Main Methods:

• Aptamer-functionalized nanoparticles (NPs) were attached to microparticle (MP) carriers conjugated with complementary sequences (CS).
• Target small biomolecules trigger the release of NPs from MP carriers.
• A resistive pulse sensor (RPS) with a micropore was used to count the released NPs.

Main Results:

• The method successfully detected a wide range of adenosine concentrations.
• Achieved a low detection limit of 0.168 nM for adenosine, which is 10 times lower than ELISA kits.
• Demonstrated high sensitivity, high throughput, and high reproducibility.

Conclusions:

• The developed nanoparticle counting method offers a simple, sensitive, and reproducible approach for detecting low-abundance small biomolecules.
• This technique holds significant potential for ultrasensitive diagnostics and biological research.
• The method provides a promising alternative to current detection strategies for small molecules.