Extending the dynamic range of electrochemical sensors using multiple modified electrodes

Area of Science:

• Electrochemistry
• Analytical Chemistry
• Materials Science

Background:

• Single electrodes have limitations in analyte detection range.
• Chemometric strategies combined with multiple electrodes can enhance sensor capabilities.
• Self-assembled monolayers are effective for electrode modification.

Purpose of the Study:

• To develop a multi-electrode sensor system for determining copper concentration over an extended dynamic range.
• To utilize chemometrics for calibrating sensor response across varying copper levels.
• To assess the feasibility of commercial production and factory calibration for such sensors.

Main Methods:

• Electrode modification with self-assembled monolayers containing copper-complexing agents (3-mercaptopropionic acid, thioctic acid, cysteine, Gly-Gly-His).
• Voltammetric analysis for copper determination across nanomolar to millimolar concentrations.
• Application of chemometric strategies to combine calibration functions from multiple electrodes.

Main Results:

• A multi-electrode system successfully determined copper concentrations from nanomolar to millimolar.
• Combining calibration functions from four electrodes yielded a more precise analyte concentration estimate (smaller variance).
• Measurement uncertainty was quantified for independently prepared electrodes, supporting commercialization.

Conclusions:

• The multi-electrode approach significantly broadens the dynamic range for analyte determination.
• This method offers a generalizable strategy for developing extended-range sensors for various analytes.
• The demonstrated accuracy and potential for factory calibration pave the way for practical sensor applications.