Core-Shell Plasmonic Nanogapped Nanostructured Material

Opportunity  

The global medical imaging reagents market size, valued at USD 12 billion in 2021,  is expected to reach USD 17 billion by 2027, expanding at a CAGR of 6.34%. The market is shifting from conventional detection methods to advanced high-throughput screening methodologies that require smaller sample volumes. Trends such as automation, rapid turnaround, multiplexing, high sensitivity and high resolution are key in the in vitro diagnostics (IVD) market. Surface Enhanced Raman Spectroscopy (SERS) is a novel technology that embodies these features. However, a major challenge in using SERS nanoprobes for quantitative detection is the inability to precisely position molecular probes inside the hotspots.  

Technology  

This invention involves a core-shell plasmonic nanostructured material with a core and at least one shell surrounding it, and is applicable in sensing, optoelectronics and theranostics. Core−shell nanogapped nanoparticles (NNPs), or nanomatryoshkas, feature a built-in dielectric gap that separates the core and shell. The nanogap size is crucial for tailoring the plasmonic coupling of the core and shell, enabling broadly tuneable localised surface plasmon resonance (LSPR) across visible and near-infrared (NIR) spectral ranges. 

This invention leverages covalent coupling of nucleophilic thiol and amine groups with quinone groups in polydopamine, providing stable and quantitative fixation inside the SERS-active nanogap. This design finds applications in ultrasensitive chemical or biological sensing, as well as new types of optical switches, interferometers and nanoantennas.  

Figure 1: a) Schematic of the synthesis of core-shell plasmonic nanogapped nanoparticles (NNPs) based on polydopamine coating, b) TEM image of core-shell magnetic NNPs. [Inset] Photograph of magnetic separation of the magnetic NNPs

Applications & Advantages  

Main application areas include quantitative detection for disease diagnostics, theronostic nanomedicine, surface enhanced spectroscopy, optoelectronics and plasmon-enhanced photochemical reactions (such as photocatalysis and solar energy conversion).  

Advantages: 

1. Nanogap size allows for broadly tunable LSPR across visible and near-infrared spectral ranges.
2. Covalent coupling of nucleophilic thiol and amine groups with quinone groups in polydopamine provides stable and quantitative fixation inside the SERS-active nanogap.