Label-free and reagentless aptamer-based sensors for small molecules

Area of Science:

• Biosensors and Nanotechnology
• Electrochemical Sensing
• Nucleic Acid Aptamer Applications

Background:

• Adenosine is a crucial biomolecule involved in various physiological processes.
• Accurate detection of adenosine is vital for diagnosing and monitoring numerous diseases.
• Existing adenosine detection methods often require complex procedures or expensive reagents.

Purpose of the Study:

• To develop a label-free, reagentless aptasensor for sensitive adenosine detection.
• To investigate the performance of an ion-selective field-effect transistor (ISFET) based aptasensor for adenosine.
• To explore electrochemical detection of adenosine using aptamer functionalized electrodes.

Main Methods:

• Fabrication of an aptasensor on an ISFET device using an aptamer/nucleic acid duplex.
• Utilizing the change in gate potential of the ISFET due to adenosine binding.
• Immobilization of the aptamer/nucleic acid duplex on an Au-electrode for electrochemical detection via Faradaic impedance spectroscopy (FIS).

Main Results:

• The ISFET-based aptasensor demonstrated label-free and reagentless detection of adenosine.
• A sensitivity limit of 5 x 10-5 M was achieved with the ISFET device.
• Electrochemical detection using FIS showed a decrease in interfacial electron-transfer resistance upon adenosine binding, indicating successful aptamer-adenosine complex formation.

Conclusions:

• The developed aptasensor offers a promising approach for sensitive and direct adenosine detection.
• The ISFET and FIS platforms provide viable alternatives for label-free electrochemical sensing of adenosine.
• This technology has potential applications in clinical diagnostics and biochemical research.