Photoelectrochemical oxygen sensor using copper-plated screen-printed carbon electrodes

Area of Science:

• Electrochemistry
• Materials Science
• Environmental Science

Background:

• Development of a novel photocatalytic amperometric sensor for dissolved oxygen (DO) determination.
• Utilizes a disposable copper-plated screen-printed carbon electrode (CuSPE) for enhanced sensitivity and reusability.
• Investigates the photoelectrochemical activity related to the formation of p-type semiconductor Cu(I)2O.

Discussion:

• Optimization of solution pH to 8 and a biased potential (E(bias)) of -0.7 V vs Ag/AgCl for maximal sensor performance.
• Achieved a linear calibration plot in the 1-8 ppm range with high sensitivity (23.51 (microA cm2)(-1) ppm(-1)) and excellent linearity (R^2 = 0.9982).
• Demonstrated good reproducibility with a relative standard deviation (RSD) of 1.87% over seven successive measurements.

Key Insights:

• The CuSPE exhibits efficient photocatalytic amperometric sensing capabilities for dissolved oxygen.
• The sensor provides accurate and reliable DO quantification, validated against a commercial DO meter in real water samples (groundwater and tap water).
• The developed sensor offers a sensitive, reproducible, and cost-effective method for DO analysis.

Outlook:

• Potential for extending the sensing principle to diverse research fields requiring dissolved oxygen monitoring.
• Future work could explore sensor modifications for different environmental matrices or analytes.
• The disposable nature of the electrode suggests applications in field-deployable or point-of-care testing scenarios.