Biothiol-Functionalized Cuprous Oxide Sensor for Dual-Mode Sensitive Hg²⁺ Detection.

Area of Science:

• Environmental Science
• Analytical Chemistry
• Materials Science

Background:

• Mercury (II) ions (Hg2+) pose significant environmental and health risks due to their high toxicity.
• Developing sensitive and rapid detection methods for Hg2+ is crucial for environmental safety and regulatory compliance.
• Existing detection methods may lack the required sensitivity, speed, or selectivity for trace-level Hg2+ analysis.

Purpose of the Study:

• To fabricate a novel electrochemical and photoelectrochemical dual-mode sensor for Hg2+ detection.
• To evaluate the sensor's performance, including its detection limits, linear ranges, stability, selectivity, and reproducibility.
• To assess the sensor's applicability for detecting Hg2+ in real-world environmental water samples.

Main Methods:

• Fabrication of a novel dual-mode sensor based on l-Cysteine (l-Cys) modified Copper(II) oxide (Cu2O).
• Utilized electrochemical and photoelectrochemical techniques for quantitative detection of Hg2+ ions.
• Validated the sensor's performance using standard solutions and analysis of river water samples.

Main Results:

• The fabricated l-Cys-Cu2O sensor demonstrated dual-mode detection capabilities for Hg2+.
• Achieved low detection limits for Hg2+ at 0.2 nM (electrochemical) and 0.01 nM (photoelectrochemical), well below EPA limits.
• Exhibited excellent stability, selectivity, and reproducibility, with high recovery rates (93.0-105.6%) in river water samples.

Conclusions:

• The developed l-Cys-Cu2O sensor is a promising platform for highly sensitive and reliable trace-level detection of Hg2+ ions.
• The dual-mode sensing approach enhances detection capabilities and offers a robust method for environmental monitoring.
• This sensor shows significant potential for practical application in assessing Hg2+ contamination in environmental water bodies.