Rapid Two-Millisecond Interrogation of Electrochemical, Aptamer-Based Sensor Response Using Intermittent Pulse...

Area of Science:

• Electrochemistry
• Biosensors
• Nucleic Acid Aptamers

Background:

• Electrochemical, aptamer-based (E-AB) sensors utilize aptamers and redox molecules to detect targets.
• Traditional voltammetric methods limit the time resolution for monitoring E-AB sensor responses.
• Rapid analysis of binding kinetics and equilibrium is crucial for advanced biosensor applications.

Purpose of the Study:

• To introduce and validate intermittent pulse amperometry (IPA) for interrogating E-AB sensors.
• To demonstrate IPA's capability for achieving high-time-resolution measurements of target binding.
• To showcase IPA's superiority over traditional voltammetric techniques for E-AB sensors.

Main Methods:

• Employing intermittent pulse amperometry (IPA) to monitor current changes on E-AB sensors.
• Tethering redox-active molecules to aptamers immobilized on an electrode surface.
• Applying potential pulses and measuring current responses with microsecond time resolution.

Main Results:

• Achieved time resolution as fast as <100 μs, significantly faster than conventional methods.
• Demonstrated quantitative relationships between sensor current, target concentration, and binding isotherms.
• Developed false-color plots for visualizing binding dynamics, analogous to fast-scan cyclic voltammetry.

Conclusions:

• IPA provides an unprecedented sub-microsecond temporal response for E-AB sensors.
• IPA is a universal method, effective for various small molecule targets like tobramycin and ATP.
• IPA enhances the ability to measure rapid sensor performance and molecular binding kinetics.