Shell-switchable SERS blocking strategy for quantitative copper ion detection using single-particle SERS probes.

Area of Science:

• Nanotechnology
• Analytical Chemistry
• Environmental Science

Background:

• Accurate detection of copper ions (Cu²⁺) is vital for environmental monitoring and human health assessment.
• Existing methods for Cu²⁺ detection often face challenges in sensitivity, selectivity, or practical application.
• Development of novel sensing strategies is crucial for reliable and efficient Cu²⁺ quantification.

Purpose of the Study:

• To develop a sensitive and selective method for Cu²⁺ quantification using single-particle surface-enhanced Raman scattering (SERS) probes.
• To design a shell-switchable SERS strategy based on Cu²⁺-induced oxidative etching of gold nanostructures.
• To demonstrate the practical applicability of the developed sensing strategy in real water samples.

Main Methods:

• Utilized single bilayered gold nanostructures as SERS probes with hidden tags.
• Employed a shell-switchable SERS blocking strategy where the gold shell acts as a switch.
• Modulated Raman intensity through Cu²⁺-induced oxidative etching for controllable signal regulation.

Main Results:

• Achieved Cu²⁺ quantification over a wide concentration range (10^-7–10^-3 M) with a limit of detection (LOD) of 33.8 nM.
• Demonstrated outstanding sensitivity and high selectivity for Cu²⁺ against various interfering metal ions.
• Successfully applied the method for Cu²⁺ detection in real water samples, confirming its reliability.

Conclusions:

• The developed shell-switchable SERS strategy provides a robust platform for sensitive and selective Cu²⁺ detection.
• The method shows significant potential for environmental monitoring and human health diagnostics.
• The system's adaptability for chemical logic operations highlights its promise for intelligent sensing applications.