A Fully Integrated and Miniaturized Heavy-metal-detection Sensor Based on Micro-patterned Reduced Graphene Oxide

Area of Science:

• Electrochemistry
• Materials Science
• Environmental Science

Background:

• Heavy metal contamination in water poses significant health risks.
• Accurate and sensitive detection methods are crucial for environmental monitoring.
• Miniaturized sensors offer advantages in portability and on-site analysis.

Purpose of the Study:

• To design and fabricate a fully integrated and highly miniaturized electrochemical sensor.
• To develop a sensor for the sensitive detection of heavy metal ions, specifically cadmium and lead.
• To evaluate the sensor's performance in real-world water samples.

Main Methods:

• Fabrication of a silicon-based electrochemical sensor.
• Micro-patterning of solvothermal-assisted reduced graphene oxide (TRGO) using lithography.
• Electrodeposition of bismuth (Bi) onto TRGO for enhanced detection.
• Square wave anodic stripping voltammetry (SWASV) for heavy metal ion analysis.

Main Results:

• The fabricated micro-sensor demonstrated a linear detection range of 1.0–120.0 μg L⁻¹ for both lead and cadmium.
• Achieved detection limits of 0.4 μg L⁻¹ for lead and 1.0 μg L⁻¹ for cadmium (S/N=3).
• The sensor showed acceptable detection performance when tested with drinking-water samples.

Conclusions:

• The developed miniaturized electrochemical sensor is effective for detecting lead and cadmium ions.
• The sensor offers high sensitivity and a wide linear range, suitable for environmental monitoring.
• The practical assessment in drinking water confirms its potential for real-world applications.