SERS-active gold lace nanoshells with built-in hotspots

Area of Science:

• Nanotechnology
• Materials Science
• Biomedical Engineering

Background:

• Multifunctional drug delivery vehicles require therapeutic and imaging capabilities.
• In situ monitoring of intracellular processes is crucial for understanding drug delivery.
• Plasmonic gold nanostructures with nanometer-scale gaps are ideal for creating SERS hot spots.

Purpose of the Study:

• To develop a simple method for preparing gold lace capsules for drug delivery and SERS applications.
• To investigate the formation and properties of gold lace capsules templated by polyurethanes.
• To demonstrate the utility of these capsules for drug loading, release, and SERS monitoring.

Main Methods:

• Synthesis of gold lace capsules (approx. 100 nm diameter) using amphiphilic polyurethanes (PUs) as templates.
• Characterization of gold lace shell morphology and nanometer-scale gaps (1-3 nm).
• Demonstration of surface-enhanced Raman spectroscopy (SERS) using 1-naphthalenethiol.
• Loading and releasing pyrene as a model hydrophobic drug and monitoring via SERS.

Main Results:

• Successfully synthesized gold lace capsules with controlled diameters (approx. 100 nm) and narrow inter-branch gaps (1-3 nm).
• The capsule morphology reflects the domain structure of the PU template.
• Demonstrated SERS capabilities for sensitive detection and monitoring of drug release.
• Established a correlation between PU molecular mass and gold shell diameter.

Conclusions:

• Gold lace capsules offer a promising platform for multifunctional drug delivery systems.
• The simple templated synthesis allows for tunable particle size and SERS hot spot formation.
• These nanostructures can facilitate in situ monitoring of drug loading, release, and intracellular processes.