Gold coated magnetic beads

The MaGOLD particles are composed of magnetic beads coated with a gold shell, which are subsequently functionalized to bind molecules of biological interest (Figure 1).

Figure 1. SEM images of MaGOLD 2.5 and MaGOLD 500 beads. Inset: SEM image of a MaGOLD 500 nanoparticle.

Gold coated magnetic beads are obtained using a proprietary procedure. The particles show excellent chemical stability, magnetic properties and an intense surface plasmon resonance in the visible-NIR region (Figure 2).

Figure 2. UV-vis absorption of the MaGOLD 500 beads

The average particle size is about 2-3 µm for the MaGOLD 2.5 and 500 nm for the MaGOLD 500 with a narrow size distribution. Nanoparticles can be conjugated with thiol-terminated polyethylene glycol containing di­fferent terminal functional groups, including amine, carboxyl, azido and biotin (Figure 3). Other sizes are available as a custom request.

Figure 3. Left: Optical microscope and Right: Fluorescence image of MaGOLD 2.5 beads functionalized with FITC-PEG-SH.

MaGOLD are the first beads on the market based on gold-coated strategy for biological separation. The main advantages of the MaGOLD technology with respect to the other commercial magnetic beads are:

1) Fast separation time
2) High chemical stability, inertness and biocompatibility
3) Possibility to tune the density of functional groups on the surface
4) Possibility to have different functional groups on the same nanoparticle

IMPORTANT: Purchases through our website are restricted to fixed amounts of beads. For larger product amounts, please contact us at the following email address: