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Nanometer-sized gold and silver particles of uniform shape and size are invaluable tools in nanotechnology (assembled arrays), light scattering (elastic - plasmon resonance; inelastic - Raman effect) and for single molecule detection. Gold nanoparticles can be attached to proteins, alkanethiols and DNA by various methods. Silver nanoparticles are evolving similar functional characteristics to their gold counterparts.

Ted Pella, Inc. is the leader in offering a wide range of both silver and gold nanoparticles for these applications. Talk to our applications engineer to find out about the new developments/applications. We are constantly developing new gold and silver colloids for new nanotechnology applications.

The nanometer sized gold colloids can be characterized as follows:

• Monodispersed gold nanoparticles supplied in water, having trace amounts of citrate, tannic acid and potassium carbonate
• Citrate stabilized with a net negative surface charge (Langmuir 2005, 21:9303-9307)
• Gold colloid pH's range from above 5 for 5nm gold to less than 9 for the larger sized particles (pH increases with size).
• Available in a size range from 2 to 250nm
• The particles are invaluable tools for light scattering, either Raman or plasmon resonance (Analytical Chemistry 1999, 71:4903-4908; Analytical BioChemistry 1998, 262:137-156)

The 2nm colloid is too small to scatter light and the solution is clear. The remaining sizes scatter light to different degrees and the solution color changes with increasing particle size.

The silver colloids are a newer offering and have not been characterized as well as the gold colloids. They are supplied in water, have a negative surface charge and are available in 4 sizes from 20 to 80nm. The smaller colloids are (20 and 40nm) are yellow in color and the larger sizes (60 and 80nm) are a light gray.

These products are known to be stable for a minimum of one year after opening. To avoid contamination after opening, it is best to handle the product under clean room conditions to avoid contamination by dust or other airborne contaminants. Temperatures for storage, after opening, can vary from 4-8°C (39-46°F) to room temperature depending on whether the application is diagnostic or research oriented. The colloid is stable on boiling and destroyed by freezing. When storing the product below 8°C (46°F) it is the customer's responsibility to ensure that their refrigerator can maintain a constant temperature in the range noted above.

NOTE: All shipments of Gold Conjugate products must be for next day delivery due to temperature requirements. No Friday (weekend) shipments.

Gold Colloids (Sols)

SDS Safety Data Sheet for Unconjugated Gold Sols (88KB PDF)

Size (nm)	Particles/ml		20 ml	Price 69.90/ea		100 ml	Price 274.00/ea
2nm	1.5 x 1014		15701-20	Qty:		15701-1	Qty:
5nm	5.0 x 1013		15702-20	Qty:		15702-1	Qty:
10nm	5.7 x 1012		15703-20	Qty:		15703-1	Qty:
15nm	1.4 x 1012		15704-20	Qty:		15704-1	Qty:
20nm	7.0 x 1011		15705-20	Qty:		15705-1	Qty:
30nm	2.0 x 1011		15706-20	Qty:		15706-1	Qty:
40nm	9.0 x 1010		15707-20	Qty:		15707-1	Qty:
50nm	4.5 x 1010		15708-20	Qty:		15708-5	Qty:
60nm	2.6 x 1010		15709-20	Qty:		15708-6	Qty:
80nm	1.1 x 1010		15710-20	Qty:		15708-8	Qty:
100nm	5.6 x 109		15711-20	Qty:		15708-9	Qty:
150nm	1.7 x 109		15712-20	Qty:		15709-10	Qty:
200nm	7.0 x 108		15713-20	Qty:		15709-11	Qty:
250nm	3.6 x 108		15714-20	Qty:		15709-12	Qty:

Silver Colloids (Sols)

MSDS Material Safety Data Sheet for Silver Colloids (89KB PDF)

Size (nm)	Particles/ml		20 ml	Price 69.90/ea		100 ml	Price 274.00/ea
20nm	7.0 x 1010		15705-20SC	Qty:		15705-1SC	Qty:
40nm	9.0 x 109		15707-20SC	Qty:		15707-1SC	Qty:
60nm	2.6 x 109		15709-20SC	Qty:		15708-6SC	Qty:
80nm	1.1 x 109		15710-20SC	Qty:		15708-8SC	Qty: