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SiFluor™ Nanoparticles

bright, non-toxic fluorescent silica nanoparticles

SiFluor™ nanoparticles are extremely bright tools for fluorescent labeling, incorporating hundreds of dye molecules into each silica particle. They show a strong continuous fluorescent signal without “on/off” phases or blinking. SiFluor particles are proprietary technology of Active Motif Chromeon, and utilize a novel method that produces a controlled size and shape. SiFluor nanoparticles are exceptionally small, available in 40 nm and 70 nm formats.

Figure 1: Size Determination of SiFluor nanoparticles showing a 20 nm radius (40 nm diameter).

Differential Size Determination of 40 nm SiFluor nanoparticles by Asymmetric Flow Field-Flow Fractionation and Multi-Angle Light Scattering (performed by PostNova GmbH/Germany).

Active Motif Chromeon’s fluorescent Chromeo™ Dyes are covalently bound inside the SiFluor core by a unique linkage molecule; this results in a uniform, reproducible distribution of the dye and prevents dye leakage. The fluorescent core is surrounded by a thin silica shell that is an effective barrier to the surrounding environment, minimizing photobleaching and photodegradation. The photostability of SiFluor nanoparticles makes them suitable for assays where high-intensity or long-term excitation are needed, or for general long-term staining experiments.

Many nanoparticles, including quantum dots, suffer from biological toxicity. SiFluor particles utilize a surface chemistry proven to be non-toxic in biological systems. Because of their biocompatibility, SiFluor nanoparticles can be used for imaging in cellular assays.

SiFluor nanoparticles are available with your choice of 3 different Chromeo Dyes or one Ruthenium-complex, which shows a long lifetime and large Stokes shift of 145 nm. The surfaces are either carboxylated, PEGylated or a combination of amine- and phosphate-groups. All modifications stabilize the particles in solution, resulting in a clear well-dispersed solution. Carboxy- and amine-groups allow for further functionalization in water or commonly used buffers.

SiFluor Nanoparticle Advantages

• Small size (40 nm or 70 nm)
• Flexibility – variety of surface modifications available
• Brightness – high intensity fluorescence for improved sensitivity
• No blinking
• pH stability
• Photostability
• No dye leakage
• No toxicity

Figure 2: Transmission electron micrograph of SiFluor nanoparticles.

Contents & Storage

All nanoparticles are supplied as a 2 mg/ml suspension in water and are guaranteed stable for at least 6 months when stored at 4°C.