Cyclic Voltammetry E-AB Sensor Stability
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Solution Overview
Problem
Existing electrochemical aptamer-based (E-AB) sensors face challenges in maintaining stability and reducing batch-to-batch and day-to-day variability when interrogated using pulse techniques, which can lead to drift and signal loss due to biofouling and monolayer desorption, and cyclic voltammetry is not commonly used for direct interrogation due to issues with signal-to-noise ratios.
Innovation Solution
Employing cyclic voltammetry (CV) to measure binding-induced changes in electron transfer kinetics by determining the peak-to-peak separation (ΔEP) in cyclic voltammograms, which is less damaging to the sensor interface and reduces variability, allowing for continuous monitoring and improved stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If pulse techniques (square wave voltammetry) are used to interrogate E-AB sensors, then signal-to-noise ratio is improved through differential removal of charging currents, but sensor stability deteriorates due to faster loss of signal and increased batch-to-batch variability
Solution Approach 1:
The patent changes the voltage program parameters from pulsed square wave to continuous cyclic voltammetry with specific triangular wave parameters (amplitude, frequency, scan rate) to achieve both good signal-to-noise ratio and sensor stability. The continuous scanning approach with optimized parameters allows maintenance of double layer capacitance information while obtaining faradaic signals.
Solution Approach 2:
The patent employs periodic cyclic voltammetry scanning with defined amplitude and frequency parameters to continuously update sensor state while maintaining stability. The periodic triangular wave scanning creates repeated opportunities to measure signal without permanently degrading the sensor interface, unlike one-time pulsed techniques.
2Reliability
If cyclic voltammetry is used for direct interrogation of E-AB sensors, then sensor stability is improved by retaining double layer capacitance information, but signal-to-noise ratio deteriorates due to large capacitive currents hiding faradaic waves
Solution Approach 1:
The patent optimizes CV parameters including scan rate, amplitude, and frequency to achieve the optimal balance where faradaic signals become distinguishable from capacitive currents. By adjusting these parameters, the system achieves sufficient signal-to-noise ratio while maintaining the stability benefits of continuous scanning.
Solution Approach 2:
The patent applies a moderate scan rate and amplitude that provides sufficient faradaic signal without excessive capacitive current. The voltage window and scan parameters are optimized to obtain just enough capacitive information for stability monitoring without overwhelming the faradaic signal, achieving partial action that satisfies both requirements.
3Productivity
If continuous monitoring is performed using traditional techniques, then real-time detection capability is improved, but sensor interface damage increases leading to faster signal loss
Solution Approach 1:
The patent replaces aggressive pulsed electrical stimulation with gentler continuous cyclic scanning. The triangular wave voltage program applies smaller, more gradual voltage changes that continuously update sensor state without the harsh electrical pulses that cause interface damage and rapid signal loss.
Solution Approach 2:
The patent implements continuous cyclic voltammetry scanning that continuously monitors sensor state without interruption. This continuous action maintains sensor interface integrity by avoiding the on/off pulsing that causes mechanical stress and chemical degradation, while providing uninterrupted real-time detection capability.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The ΔEP-based method provides stable and reliable measurements with reduced batch-to-batch and day-to-day variability, retaining sensor capacitance information and enabling sub-second interrogation competitive with other techniques, while maintaining sensor stability over time.
Implementation Method 1
causing a change in the electron transfer rate between the reporter and the electrode, which can be easily measured electrochemically
Implementation Method 2
generating one or more cyclic voltammograms from the electrochemical sensor using cyclic voltammetry (CV); determining a change in a target peak-to-peak separation, ΔEP,T, from the cyclic voltammograms
Data Source
AI summary
Provided herein are methods of detecting target molecules using electrochemical sensors that comprise biomolecular receptor-bound redox reporters. Related systems and computer readable media are also provided.