Ultrasensitive, Selectivity Detection of Mercury Ion Using a Novel Localized Surface Plasmon Resonance Biosensor

Area of Science:

• Environmental Science
• Analytical Chemistry
• Nanotechnology

Background:

• Mercury ions (Hg²⁺) are toxic pollutants posing risks to health and ecosystems.
• Sensitive and selective detection methods for Hg²⁺ are crucial for environmental protection.

Purpose of the Study:

• To develop a highly sensitive and selective localized surface plasmon resonance (LSPR) sensor for mercury ion detection.
• To utilize 4-mercaptopyridine-functionalized gold nanoparticles (4-MPY-AuNPs) for Hg²⁺ sensing.

Main Methods:

• Synthesis of 4-mercaptopyridine-functionalized gold nanoparticles (4-MPY-AuNPs).
• Immobilization of 4-MPY-AuNPs onto quartz slides to create an LSPR sensor.
• Detection of Hg²⁺ via selective coordination with 4-MPY and formation of a sandwich architecture.

Main Results:

• The LSPR sensor demonstrated high specificity for Hg²⁺ detection.
• Achieved a linear dynamic range of 1 × 10^-9–6 × 10^-7 mol L^-1.
• Obtained a limit of detection (LOD) of 3.2 × 10^-10 mol L^-1, one order of magnitude lower than existing methods.

Conclusions:

• The developed label-free LSPR sensor offers superior sensitivity and selectivity for Hg²⁺ detection.
• This cost-effective method shows significant potential for real-world environmental monitoring applications.
• The sensor design facilitates enhanced sensitivity through a sandwich architecture.