Voltammetric Analysis of Quasi-Reversible Kinetics in Aptamer Self-Assembled Monolayers: Toward Rational E-AB Sensor...

Area of Science:

• Electrochemistry
• Biosensors
• Analytical Chemistry

Background:

• Electrochemical aptamer-based (E-AB) sensors are crucial for detecting various targets.
• Understanding electron-transfer kinetics and aptamer dynamics is vital for E-AB sensor optimization.
• Limited systematic investigations exist on these fundamental processes.

Purpose of the Study:

• To comprehensively characterize the voltammetric behavior of an E-AB sensor for vancomycin detection.
• To investigate the influence of charge transfer kinetics and aptamer conformation on sensor response.
• To develop a robust calibration strategy mitigating sensor variability.

Main Methods:

• Cyclic voltammetry (CV) and square wave voltammetry (SWV) were employed for electrochemical characterization.
• The Laviron method and peak-to-peak separation analysis quantified electron-transfer rate constants.
• A ratiometric SWV approach using dual frequencies was developed for calibration.

Main Results:

• Electron-transfer rate constants significantly increased upon vancomycin binding.
• Aptamer packing density was found to be interdependent with peak current.
• The ratiometric SWV method reduced sensor variability (RSD) from 10.5% to 2.2%.

Conclusions:

• Systematic voltammetric analysis provides critical insights into E-AB sensor operation.
• A robust ratiometric SWV approach enhances calibration and reduces sensor-to-sensor variability.
• This work facilitates rational design and optimization of E-AB sensors for practical applications.