Twist-assisted high sensitivity chiral fiber sensor for Cd²⁺ concentration detection

Area of Science:

• Environmental Science
• Analytical Chemistry
• Optical Sensing

Background:

• Accurate and affordable monitoring of heavy metals like cadmium (Cd²⁺) in water is crucial for human health.
• Existing methods for heavy metal detection can be costly or lack real-time capabilities.

Purpose of the Study:

• To develop a highly accurate and cost-effective sensor for detecting Cd²⁺ concentration in environmental water solutions.
• To demonstrate a novel twisted fiber-based sensing mechanism for real-time heavy metal monitoring.

Main Methods:

• A twisted single-core fiber coated with a propylene thiourea membrane was designed to absorb Cd²⁺.
• The twisting effect induced light scattering, optical coupling, and interference within the fiber.
• Transmission spectra were analyzed to correlate interference dip characteristics with Cd²⁺ concentration.

Main Results:

• The sensor demonstrated a linear response in both the position and amplitude of interference dips to Cd²⁺ concentration.
• Detection limits reached as low as 10^-11 mol/L for Cd²⁺.
• Bimodal calibration enabled accurate and real-time monitoring in a stable and non-toxic manner.

Conclusions:

• The twisted fiber sensor offers a promising solution for sensitive and real-time detection of heavy metals in water.
• This technology has significant potential for applications in biochemical sensing and integrated optical systems.
• The sensor's stability, non-toxic nature, and cost-effectiveness enhance its practical applicability.