Separation of Stabilized MOPS Gold Nanostars by Density Gradient Centrifugation

Area of Science:

• Nanotechnology
• Materials Science
• Biochemistry

Background:

• Gold nanostars (AuNS) are valuable nanomaterials with applications in diagnostics and therapeutics.
• Maintaining the structural integrity and homogeneity of AuNS post-synthesis is crucial for their reliable application.
• Current methods for AuNS stabilization and separation are often limited in efficiency and scope.

Purpose of the Study:

• To develop a method for stabilizing gold nanostars (AuNS) synthesized using 3-(N-morpholino)propanesulfonic acid.
• To establish a postsynthetic separation technique for AuNS based on their morphological characteristics.
• To optimize storage conditions for enhanced nanoparticle stability and homogeneity.

Main Methods:

• Synthesis of AuNS using a morpholine-based Good's buffer.
• Resuspension of AuNS in ultrapure water to assess shape stability over time.
• Rate-zonal centrifugation through a linear sucrose gradient for nanoparticle separation.
• Optimization of storage conditions for improved structural homogeneity.

Main Results:

• Resuspension in ultrapure water significantly improved AuNS shape stability for over 30 days.
• Rate-zonal centrifugation effectively sorted AuNS based on branch length and number in a single round.
• Optimized storage conditions led to enhanced structural homogeneity and stability of the nanoparticles.
• A robust method for sorting AuNS by size and shape was successfully established.

Conclusions:

• Ultrapure water is an effective medium for stabilizing AuNS, extending their structural integrity.
• Rate-zonal centrifugation provides an efficient and robust method for separating AuNS by morphology.
• The developed methods offer improved control over AuNS characteristics, facilitating their use in advanced applications.