Highly sensitive and selective carbon dot sensor for hydrogen sulfide based on dual quenching effect

Area of Science:

• Materials Science
• Analytical Chemistry
• Environmental Science

Background:

• Hydrogen sulfide (H2S) poses significant environmental and health risks.
• Accurate H2S detection is crucial for industrial safety and environmental monitoring.
• Existing H2S sensors often require improvement in sensitivity and response time.

Purpose of the Study:

• To develop a novel, highly sensitive H2S detection method.
• To create a robust fluorescent sensing film for trace H2S detection.
• To enable compact, portable, and on-site H2S monitoring.

Main Methods:

• Synthesis of silver ion-doped nitrogen-sulfur co-doped carbon dots (N, S-CDs@Ag+).
• Utilizing a dual-quenching mechanism (DQE) for H2S detection.
• Fabrication of a fluorescent sensing film using N, S-CDs@Ag+ on silica microspheres (SM@PVA) via layer-by-layer assembly.

Main Results:

• The N, S-CDs@Ag+ sensor demonstrated a limit of detection (LoD) of 0.83 nM for H2S in solution within a 10-120 nM range, with a 1-minute response time.
• The N, S-CDs@Ag+/SM@PVA film sensor achieved an LoD of 0.41 ppm for gaseous H2S in a 1-50 ppm range, with a 5-minute response time.
• The film sensor exhibited stable performance, electromagnetic interference resistance, and suitability for in-field detection.

Conclusions:

• The developed N, S-CDs@Ag+ material and its assembled film offer a promising platform for sensitive and rapid trace H2S detection.
• The sensor system shows potential for integration into compact, portable devices for on-site H2S monitoring.
• This technology addresses the need for improved H2S sensing in environmental and industrial applications.