Gold Silica Core Shell Nanoparticles (Au/SiO2, 99.9%, APS: 80-100nm, Metal Core)

Gold-Silica Core-Shell Nanoparticles

Applications:

Biomedical Applications

Drug Delivery: Gold-silica nanoparticles are extensively explored as drug delivery carriers due to their ability to encapsulate hydrophobic drugs in the silica shell or load them onto the gold core. The silica shell can also be modified with specific ligands (e.g., antibodies, peptides) to enable targeted drug delivery. This allows for controlled release of the drug at the site of interest, enhancing therapeutic efficacy and minimizing side effects.

Imaging and Diagnostics: Gold-silica core-shell nanoparticles are used in imaging applications such as X-ray, CT scans, and optical imaging. The gold core provides strong contrast in imaging modalities like photoacoustic imaging (PAI) and optical coherence tomography (OCT), while the silica shell improves the stability and biocompatibility of the nanoparticles. Additionally, the gold core’s SPR properties make these nanoparticles useful in surface-enhanced Raman spectroscopy (SERS) for highly sensitive detection of biomarkers.

Cancer Therapy (Theranostics): Au-SiO₂ nanoparticles are a promising tool in theranostics, a combined diagnostic and therapeutic approach. They can be used in photothermal therapy (PTT), where the gold core absorbs near-infrared light and converts it into heat, selectively killing cancer cells. The silica shell provides the stability needed for drug loading and delivery, allowing for simultaneous imaging and therapy. This dual functionality makes Au-SiO₂ nanoparticles highly effective in cancer treatment.

Biosensing and Detection

Biosensors: The gold core in Au-SiO₂ nanoparticles exhibits surface plasmon resonance (SPR), a phenomenon that is highly sensitive to changes in the local environment, such as binding events on the nanoparticle surface. This property makes Au-SiO₂ nanoparticles excellent for use in biosensors. The silica shell can be functionalized with antibodies, enzymes, or other biomolecules to capture specific targets, and the gold core can be used for SPR-based detection. This allows for sensitive detection of biomolecules like DNA, proteins, and small molecules.

Environmental Monitoring: Au-SiO₂ nanoparticles are also used in the detection of environmental pollutants, such as heavy metals, pesticides, or toxic gases. The nanoparticles can be engineered to selectively bind to pollutants, and the gold core’s SPR properties allow for optical sensing and real-time monitoring.

Catalysis

Catalysis and Catalytic Supports: Gold nanoparticles have shown excellent catalytic activity in various reactions, such as oxidation, hydrogenation, and CO oxidation. The silica shell can enhance the stability of the gold nanoparticles under harsh catalytic conditions, prevent aggregation, and provide additional surface area for interaction with reactants. The shell can also be functionalized with various chemical groups to enhance the selectivity of the catalytic process. This makes Au-SiO₂ core-shell nanoparticles valuable for green chemistry applications and heterogeneous catalysis.

CO Oxidation: Au-SiO₂ core-shell nanoparticles are often used in the catalytic oxidation of carbon monoxide (CO). The gold core provides a high surface area for adsorption, while the silica shell stabilizes the nanoparticle and prevents sintering under high temperatures.

Photothermal Therapy

Cancer Treatment: As mentioned earlier, the gold core in Au-SiO₂ nanoparticles can absorb near-infrared (NIR) light and convert it into heat, making these nanoparticles ideal for photothermal therapy (PTT) in cancer treatment. The silica shell not only helps in stabilizing the nanoparticles but also can be loaded with chemotherapeutic agents to provide a combination of photothermal therapy and chemotherapy. The dual action of heat and drug delivery can enhance therapeutic outcomes while minimizing damage to healthy tissues.