Sensitive detection of cadmium ions based on a quantum-dot-mediated fluorescent visualization sensor

Area of Science:

• Materials Science
• Analytical Chemistry
• Nanotechnology

Background:

• Cadmium ions (Cd²⁺) pose significant environmental and health risks.
• Accurate and sensitive detection methods for Cd²⁺ are crucial for monitoring and remediation.
• Existing detection techniques may lack portability, real-time capabilities, or sensitivity.

Purpose of the Study:

• To develop a sensitive ratiometric fluorescent sensor for Cd²⁺ detection.
• To utilize carbon quantum dots (CQDs) as a reference and CdTe quantum dots (CdTe QDs) as a signal probe.
• To enable visualized and quantitative detection of Cd²⁺ in real-world samples, including integration with smartphone platforms.

Main Methods:

• Construction of a ratiometric fluorescent sensor using CQDs and CdTe QDs.
• Utilizing blue fluorescence from CQDs as a reference and red fluorescence from CdTe QDs as a response signal.
• Testing selectivity and sensitivity, determining the limit of detection (LOD) and detection range.
• Application of the sensor for Cd²⁺ determination in rice samples.
• Integration of the sensor with a smartphone for portable detection.

Main Results:

• The sensor demonstrated high selectivity and sensitivity towards Cd²⁺.
• Achieved a low limit of detection (LOD) of 0.018 μM for Cd²⁺.
• Successfully quantified Cd²⁺ in real rice samples.
• Developed a smartphone-integrated platform for visualized and quantitative Cd²⁺ detection.

Conclusions:

• The developed CQDs/CdTe QDs ratiometric fluorescent sensor provides a sensitive and selective method for Cd²⁺ detection.
• The smartphone-integrated system offers a rapid, portable, and on-site solution for real-time Cd²⁺ monitoring.
• This work contributes to advanced visualization analysis strategies for environmental and food safety applications.