Micro and nanoparticles for biological applications

Type of particle

A selection of micro and nanoparticles based on silica, gold, graphene, and hydrogel for applications in biology and biotechnology.


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Neutravidin-functionalized Magnetic microbeads for selective separation

 

eMAG Si

Neutravidin-functionalized silica magnetic beads

eMAG Si magnetic beads are 2.5 µm silica magnetic beads functionalized with NeutravidinTM for the capture of biotinylated molecules or biotinylated antibodies. Quality controls are performed to ensure the maximum quality of our product. We perform three main controls in the production pipeline: (i) test of size distribution, (ii) test of paramagnetic activity and (iii) test of the density of functionalization. The density of functionalization of eMAG Si is certified by the labeling of fluorescent biotinylated molecules (Figure 1). The binding capacity calculated using Biotin-ATTO647N is 15 nmol biotinylated molecules/ml beads.

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Figure 1. Fluorescence microscopy analysis of eMAG Si stained with Biotin-ATTO488

 

MAGAR-cN

Neutravidin-functionalized porous agarose magnetic beads

MAGARTM magnetic beads are functionalized with NeutravidinTM for the capture of biotinylated molecules or biotinylated antibodies. Quality controls are performed to ensure the maximum quality of our product. We perform three main controls in the production pipeline: (i) test of size distribution, (ii) test of paramagnetic activity and (iii) test of the density of functionalization. The average particle size is 50 μm. MAGAR-cN are also available as non-crosslinked particles (MAGAR-N). These innovative particles are suitable for experiments where an ultra-low nonspecific binding is desirable. The density of functionalization of MAGAR-cN is certified by the labeling of fluorescent biotinylated molecules (Figure 2).

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Figure 2. Fluorescence microscopy analysis of MAGAR-cN stained with Biotin-ATTO488

The main advantages of our MAGAR technology are:
(a) low non-specific binding;
(b) the competition on price, thanks to a technology that can reduce the cost of production;
(c) the high stability in suspension, maximizing the binding properties.
The binding capacity is comparable to other commercial products.

Instructions MAGAR-cN for IP
Instructions MAGAR-cN_for capturing and eluting biotinylated proteins

Immagina BioTechnology offers a service of custom beads synthesis that allow customers:
(i) to choose specific functionalizations and (ii) to fine-tune the density of the functional groups on the bead.

 


Gold coated magnetic beads for selective separation

 

Applications: Biological separation, thiol chemistry, Raman Spectroscopy.

 

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).

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Figure 1. Left: Synthesis of MaGOLD. Right: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).

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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.

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Figure 3. Left: Optical microscope image of MaGOLD 2.5 beads. 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.


Graphene-doped magnetic beads for separation and purification (MaGO)

Applications: Separation and purification of basic dyes and aromatic molecules

 

Immagina MaGO beads have a magnetic core embedded in an agarose structure. Beads are doped with Graphene Oxide or Reduced Graphene Oxide. MaGO are spherical beads with dimensions of about 50 µm. The adsorption capacity of MaGO sample was tested using a set of aromatic positively charged dyes (Nile Blue, Methylene Blue, Rhodamine 6G, and Crystal Violet). The results are reported in Figure 1. All the molecules tested showed a high value of adsorption capacity and very fast adsorption kinetics.

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Figure 1.Up: UV-visible spectroscopy of the NB, CV, MB, and Rh6G dyes solutions and the supernatants after absorption for 1 minute with MaGO Table: Values of absorption capacity (Qt) and the absorption time of the tested molecules.

TetramethylRhodamine molecules (TAMRA) and TAMRA-labelled antibody (IgG-TAMRA) incubated with MaGO beads for 5-10 seconds followed by magnetic separation of the beads (Figure 2). As revealed from the Uv-Vis absorption spectra and spectrofluorometric analysis, MaGO beads can efficiently remove the free dye while the TAMRA-labelled antibody is still in solution (< 10% reduction).

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Figure 2. A and B UV Vis of IgG-TAMRA and free TAMRA dye (black lines) incubated with MaGO beads followed by vortexing for 5 seconds (red lines). C and D. Fluorescence emission of IgG-TAMRA and free TAMRA dye (black lines) incubated with MaGO beads followed by vortexing for 5 seconds (red lines).

Fast Protocol for free dye/protein separation

  • Vortex the MaGO beads tube for 30 seconds
  • Put the required MaGO beads volume in a new 1.5 mL tube
  • Place the tube on the magnet to separate the beads. Remove the supernatant
  • Resuspend the beads in your dye-protein mixture
  • Vortex for 5-10 seconds
  • Place immediately the tube on the magnet to separate the beads. Remove the supernatant enriched with your labeled protein
  • Discard the beads containing the free dye

Palladium decorated Graphene-doped magnetic beads for catalysis (MarGO-Xm)

 

Applications: Catalysis

Video of Methylene Blue reduction with Sodium Borohydride in water catalyzed by MarGO-Xm

Immagina MarGO-Xm beads are palladium-decorated graphene magnetic beads. Beads are functionalized with palladium nanoparticles. MarGO-Xm are spherical beads with dimensions of about 50 µm.
MarGO-Xm particles were tested as catalysts for the catalytic reduction of molecules by sodium boron hydride. These reactions in the absence of catalysts are very slow and require days to reach completion. The metallic nanoparticles present on the surface of the graphene can increase the speed of the reaction by several orders of magnitude. 4-Nitrophenol (4-NP), Congo red (CR), and Methylene Blue (MB) were chosen as models for testing the catalytic properties of the MarGO-Xm palladium beads. The Turnover Frequency (TOF) values of the aforementioned reactions are reported in Table 2. The efficiency in the degradation of Rh6G, CR, MB, and 4-NP compared with those reported in literature ranks MarGO-Pd among the more active catalyst.

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Table 2: TOF values of MarGO-Xm in different reaction conditions.

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Figure 3. UV-Vis spectra of 4-NP reduction before (black) and 1 minute after the addition of the MarGO-Xm beads (red).

Standard Protocol

  • Vortex the MarGO-Xm beads tube for 5 seconds
  • Put the required MarGO-Xm beads volume in a new 1.5 mL tube
  • Place the tube on the magnet to separate the beads. Remove the supernatant
  • Resuspend the beads in your reaction mixture
  • Vortex for 5 seconds
  • Place the tube in a sonication bath and kept it until the reaction is complete, or alternatively mix with a thermomixer (do not use magnetic stirrer)
  • Place the tube on the magnet to separate the beads. Remove the supernatant to collect the product.
  • Discard the beads

Silica nanoparticles

 

Applications

Biological separations/functionalization, drug delivery and optical imaging.

 

EasySi are silica nanospheres with diameters from 50 nm to 500 nm with or without a fluorescent core. EasySi are available with bare and amine-terminated surfaces. Other sizes (up to 2.6 µm), functional surfaces and larger quantities (up to 5 g) are available as a custom request. Particles are stable in water and provided as solution at 10-50 mg/mL; standard silica particles are provided in water and amine-terminated silica particles are provided in 0.1 M acetate buffer.

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Figure 1. Left: Hydrodynamic diameter distributions measured with Malvern Zetasizer Nano ZS. The mean diameter is reported for each graph. Right: Glass bottle withEasySi particles of 140 nm.

– DLS data provided with every batch
– Sizes from 30-500 nm with polydispersity index in DLS < 0.2 (< 0.1 for beads > 100 nm)
– Available with bare silica and amine-terminated surfaces
– Provided in water for bare silica and 0.1 M acetate buffer for amine-terminated silica
– TEM data provided with additional 250 €/order
– Other sizes, surfaces (e.g. sulfhydryl) and larger quantities are available as a custom request.

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Figure 2. Left: TEM images of 70 nm EasySi nanoparticles. Right: Optical image of 2.5 µm EasySi particles.

EasySi-Fluo
Silica technology

With our EasySi-Fluo technology, we can deliver tailored fluorescent nanoparticles specifically engineered for your needs. Do not hesitate to contact us to speed up your R&D.
As an example, our product EasySi-Rh6G are spherical beads of 50-200 nm with a high fluorescent core (Excitation 520 nm) / Emission max = 545). Custom modifications available upon request.

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Figure 3. left: EasySi-Rh6G and free Rhodamine 6G fluorescence emission. Right: EasySi -Alexa647 and free Alexa647 fluorescence emission

 

– DLS data provided with every batch
– Sizes from 50-200 nm with polydispersity index in DLS < 0.2 (< 0.1 for beads > 100 nm)
– Available with bare silica and amine-terminated surfaces
– Provided in water for bare silica and 0.1 M acetate buffer for amine-terminated silica
– TEM data provided with an additional 250 €/order
– Other sizes, surfaces (e.g. sulfhydryl) and larger quantities are available as a custom request.

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Figure 4. Left: EasySi doped with different dyes; Rhodamine 6G, Fluorescein, and AlexaFluor647. Right: Emission of EasySi-Rh6G under UV illumination.

Shape:  spherical
Application: Biological imaging, drug delivery, and optical applications
Storage and Handling: +4°C Do not freeze
Packaging: Plastic vials

MSDS:

Type of particle
IMMAGINA BioTechnology’s General Terms and Conditions