Versatile Sensitive Localized Surface Plasmon Resonance Sensor Based on Core-Shell Gold Nanorods for the Determination of Mercury(II) and Cysteine

Abstract

A versatile sensitive localized surface plasmon resonance sensor was fabricated for the determination of mercury(II) and cysteine. The determination of mercury(II) was performed by taking advantage of the affinity between core-shell nanostructure and mercury to form a nanocomposite, leading to significant changes of localized surface plasmon resonance properties. The outstanding selectivity and sensitivity of the method provide a unique way to determine mercury(II) to concentrations as low as 5.00 × 10⁻⁸ M in aqueous solution. In addition, a strategy of orientation axially (end-to-end) assembly of core-shell gold nanorods at acidic medium was been developed that resulted in coupling of the plasmon band of core-shell gold nanorods, and was the basis of determining cysteine. An ultra-sensitive assay for the determination of cysteine was subsequently developed and levels of cysteine as low as 10⁻¹² M can be determined. Compared with other gold nanorods-based sensors requiring molecular modification, these two approaches are simple in aqueous solution because of the unmodified design.

Keywords:

• Assembly
• Core-shell gold nanorods
• Cysteine
• Localized surface plasmon resonance
• Mercury
• Sensor

Acknowledgments

This work was supported by Natural Science Foundation of China (21075035) and the Key Laboratory of Inorganic Coating Materials, Chinese Academy of Sciences.