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Nanopartz™ Accurate™ Spherical Gold Nanoparticles

Nanopartz™ Accurate™ Spherical Gold Nanoparticles are spherical gold nanoparticles manufactured using proprietary methods that result in exact sizes, highly monodisperse sizes and shapes, long shelf lives, along with significantly improved reactivity. Diameters from 1.8nm to 150nm with size accuracies up to 0.1nm and size variances less than 2% at sizes larger than 40nm. Peak SPRs range from 505nm to 612nm. Every batch is completely characterized including size, monodispersity, aggregation, residual chemicals, and concentration. A Certificate of Analysis (COA) is provided for every order exhibiting TEM and UV-VIS images and data, as well as DLS data. Every product is in stock (99%) and is shipped same day. This product comes in two concentrations, regular OD=1 (0.05mg/mL, Part Number A11), and highly concentrated OD=100 (5mg/mL, Part Number, AC11) in DI water, purified of residual reactants to <0.1%. These particles are are available non-covalently capped with our own proprietary carboxylic acid, citrate, and many other ligands including charged ligands (see below). In all cases, these capping agents are readily replaced with covalent and charge chemistries. Kits (Part Number AK11) for both 25mL and 1mL volumes are offered.

Part #A11 Nanopartz Accurate Spherical Gold Nanoparticles OD=1

 

Part

Number

Diam (nm)
Peak SPR (nm)
Optical Density
NPS/ml
Wt. conc (ug/ml)
Wt. %
PPM
Molarity (pM)
A11-1.8
1.8
505-508
1
8.38E+14
50
0.01%
50
1.40E+06
A11-2.2
2.2
505-508
1
4.59E+14
50
0.01%
50
7.65E+05
A11-3
3
505-508
1
1.81E+14
50
0.01%
50
3.02E+05
A11-4
4
505-508
1
7.64E+13
50
0.01%
50
1.27E+05
A11-5
5
505-508
1
3.91E+13
50
0.01%
50
6.52E+04
A11-10
10
514-520
1
4.89E+12
50
0.01%
50
8.14E+03
A11-15
15
514-520
1
1.45E+12
50
0.01%
50
2.41E+03
A11-20
20
514-520
1
6.11E+11
50
0.01%
50
1.02E+03
A11-25
25
514-520
1
3.13E+11
50
0.01%
50
521
A11-30
30
523
1
1.81E+11
50
0.01%
50
302
A11-35
35
526
1
1.14E+11
50
0.01%
50
190
A11-40
40
527
1
7.64E+10
50
0.01%
50
127
A11-45
45
529
1
5.36E+10
50
0.01%
50
89.4
A11-50
50
531
1
3.91E+10
50
0.01%
50
65.2
A11-55
55
533
1
2.94E+10
50
0.01%
50
49
A11-60
60
536
1
2.26E+10
50
0.01%
50
37.7
A11-65
65
539
1
1.78E+10
50
0.01%
50
29.7
A11-70
70
542
1
1.42E+10
50
0.01%
50
23.7
A11-75
75
545
1
1.16E+10
50
0.01%
50
19.3
A11-80
80
549
1
9.54E+09
50
0.01%
50
15.9
A11-85
85
553
1
7.96E+09
50
0.01%
50
13.3
A11-90
90
558
1
6.70E+09
50
0.01%
50
11.2
A11-95
95
563
1
5.70E+09
50
0.01%
50
9.5
A11-100
100
569
1
4.89E+09
50
0.01%
50
8.1
A11-125
125
600
1
2.50E+09
50
0.01%
50
4.2
A11-150
150
612
1
1.45E+09
50
0.01%
50
2.4

 

 

Part #AC11 Nanopartz Accurate Concentrated Spherical Gold Nanoparticles OD=100

 

Part #
Diameter (nm)
Peak SPR (nm)
Optical Density
NPS/ml
Wt. conc (mg/ml)
Wt. %
PPM
Molarity (pM)
AC11-1.8
1.8
505-508
100
8.38E+16
5
0.50%
5000
1.40E+08
AC11-2.2
2.2
505-508
100
4.59E+16
5
0.50%
5000
7.65E+07
AC11-3
3
505-508
100
1.81E+16
5
0.50%
5000
3.02E+07
AC11-4
4
505-508
100
7.64E+15
5
0.50%
5000
1.27E+07
AC11-5
5
505-508
100
3.91E+15
5
0.50%
5000
6.52E+06
AC11-10
10
514-520
100
4.89E+14
5
0.50%
5000
8.14E+05
AC11-15
15
514-520
100
1.45E+14
5
0.50%
5000
2.41E+05
AC11-20
20
514-520
100
6.11E+13
5
0.50%
5000
1.02E+05
AC11-25
25
514-520
100
3.13E+13
5
0.50%
5000
5.21E+04
AC11-30
30
523
100
1.81E+13
5
0.50%
5000
3.02E+04
AC11-35
35
526
100
1.14E+13
5
0.50%
5000
1.90E+04
AC11-40
40
527
100
7.64E+12
5
0.50%
5000
1.27E+04
AC11-45
45
529
100
5.36E+12
5
0.50%
5000
8.94E+03
AC11-50
50
531
100
3.91E+12
5
0.50%
5000
6.52E+03
AC11-55
55
533
100
2.94E+12
5
0.50%
5000
4.90E+03
AC11-60
60
536
100
2.26E+12
5
0.50%
5000
3.77E+03
AC11-65
65
539
100
1.78E+12
5
0.50%
5000
2.97E+03
AC11-70
70
542
100
1.42E+12
5
0.50%
5000
2.37E+03
AC11-75
75
545
100
1.16E+12
5
0.50%
5000
1.93E+03
AC11-80
80
549
100
9.54E+11
5
0.50%
5000
1.59E+03
AC11-85
85
553
100
7.96E+11
5
0.50%
5000
1.33E+03
AC11-90
90
558
100
6.70E+11
5
0.50%
5000
1.12E+03
AC11-95
95
563
100
5.70E+11
5
0.50%
5000
949.9
AC11-100
100
569
100
4.89E+11
5
0.50%
5000
814.5
AC11-125
125
600
100
2.50E+11
5
0.50%
5000
417
AC11-150
150
612
100
1.45E+11
5
0.50%
5000
241.3

 

 

A11

Example part number is A11-10-CIT-DIH-25 where:

A11 - Product family number for Nanopartz Spherical Gold Nanoparticles at OD=1, other option is AC11 which is concentrated at OD=100

10 - Sphere diameter in nanometers. Other choices are 1.8 to 150

CIT - Capping ligand, in this case Citrate. Other choices are CTAB, PAA, PVP, PEI, PAH, PSS, negative charged polymer, neutral charged polymer, positive charged polymer

DIH - Buffer, in this case 18MEG DI water. Other choices, depending on the capping ligand are PBS, MES, Sodium Borate, TRIS

25 - Volume (mL). Other choices are 100mL, 500mL, 1L, 2L.

Certified Sterilized - Though the product come sterilized, this option includes testing and certification.

Endotoxin Purified - The product is endotoxin purified and certified.

Family Part #
Sphere Diameter (nm)
Capping Ligand
Buffer
Volume (mL)
A11
1.8
Nanopartz Carboxylic Acid
DI Water (DIH)
25
2.2
Citrate
PBS
100
3
PEI
MES
500
4
PAH
Sodium Borate
1000
5
PAA
TRIS
2000
10
PVP
15
BSA
20
CTAB
25
Pos Polymer
30
Neg Polymer
35
Neut Polymer
40
45
50
55
60
65
70
75
80
85
90
95
100
125
150

Example part number is AC11-10-CIT-DIH-1 where:

AC11 - Product family number for Nanopartz Spherical Gold Nanoparticles at OD=1, other option is AC11 which is concentrated at OD=100

10 - Sphere diameter in nanometers. Other choices are 1.8 to 150

CIT - Capping ligand, in this case Citrate. Other choice is Nanopartz Carboxylic Acid.

DIH - Buffer, in this case 18MEG DI water.

1 - Volume (mL). Other choices are 5 and 10 mL.

Certified Sterilized - Though the product come sterilized, this option includes testing and certification.

Endotoxin Purified - The product is endotoxin purified and certified.

Family Part #
Sphere Diameter (nm)
Capping Ligand
Buffer
Volume (mL)
AC11
1.8
Nanopartz Carboxylic Acid
DI Water (DIH)
1
2.2
Citrate
5
3
10
4
5
10
15
20
25
30
35
40
45
50
55
60
65
70
75
80
85
90
95
100
125
150

 

Home » A- Unfunctionalized Nanoparticles » A11 Spherical Gold Nanoparticles
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Accurate SGNPs 1.8-150nm
Accurate SGNPs 1.8-150nm
Part# A11-(SIZE)-(LIGAND)-(VOL)-(BUFFER)
Buffer
18MEG DI Water
Sterilization
Certified Sterilized (+$150.00)
Endotoxin
Endotoxin Purified and Certified (+$250.00)
Price: $100.00
A11-KIT-1mL
A11-KIT-1mL
Accurate Spherical Gold Nanoparticles, 1mL KIT Part# A11-KIT-1mL; Minimum Qty. 8, 1mL ea. in 18MEG DI Water; Enter Qty. for each size. Only for online orders. $30 each.
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
Price: $0.00
Accurate Concentrated SGNPs  1.8-150nm
Accurate Concentrated SGNPs 1.8-150nm
Part# AC11-(SIZE)-(LIGAND)-(VOL)-DI Water
Sterilization
Certified Sterilized (+$150.00)
Endotoxin
Endotoxin Purified and Certified (+$250.00)
Price: $400.00
Accurate SGNPs 10-90nm 25mL KIT
Accurate SGNPs 10-90nm 25mL KIT
Part# AK11-(SIZE)-25mL; Minimum Qty. 4, 25mL ea. in 18MEG DI Water; Enter Qty. for each size.
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
Price: $0.00

 

 

Part #
Diam (nm)
Peak SPR (nm)
Optical Density (1cm)
NPS/ml
Wt. conc (ug/ml)
Wt. %
PPM
Molarity (pM)
Molar Ext. (M-1cm-1)
Absorption Molar Ext. (M-1cm-1)
Scattering Molar Ext. (M-1cm-1)
Size Dispersity %PDI
Notes
A11-1.8
1.8
505-508
1
8.38E+14
50
0.01%
50
1.40E+06
7.16E+05
7.16E+05
0.00E+00
<35%
1,3
A11-2.2
2.2
505-508
1
4.59E+14
50
0.01%
50
7.65E+05
1.31E+06
1.31E+06
0.00E+00
<25%
1,3
A11-3
3
505-508
1
1.81E+14
50
0.01%
50
3.02E+05
3.32E+06
3.32E+06
0.00E+00
<20%
1,3
A11-4
4
505-508
1
7.64E+13
50
0.01%
50
1.27E+05
7.86E+06
7.86E+06
0.00E+00
<20%
1,3
A11-5
5
505-508
1
3.91E+13
50
0.01%
50
6.52E+04
1.53E+07
1.53E+07
0.00E+00
<20%
2,3
A11-10
10
514-520
1
4.89E+12
50
0.01%
50
8.14E+03
1.23E+08
1.23E+08
0.00E+00
<15%
2,3
A11-15
15
514-520
1
1.45E+12
50
0.01%
50
2.41E+03
4.14E+08
4.14E+08
0.00E+00
<15%
2,3
A11-20
20
514-520
1
6.11E+11
50
0.01%
50
1.02E+03
9.82E+08
9.82E+08
0.00E+00
<10%
2,3
A11-25
25
514-520
1
3.13E+11
50
0.01%
50
521
1.92E+09
1.92E+09
0.00E+00
<10%
2
A11-30
30
523
1
1.81E+11
50
0.01%
50
302
3.32E+09
3.32E+09
0.00E+00
<6%
2
A11-35
35
526
1
1.14E+11
50
0.01%
50
190
5.26E+09
5.26E+09
0.00E+00
<6%
2
A11-40
40
527
1
7.64E+10
50
0.01%
50
127
7.86E+09
7.84E+09
2.28E+07
<4%
2
A11-45
45
529
1
5.36E+10
50
0.01%
50
89.4
1.12E+10
1.10E+10
2.06E+08
<4%
2
A11-50
50
531
1
3.91E+10
50
0.01%
50
65.2
1.53E+10
1.48E+10
5.97E+08
<4%
2
A11-55
55
533
1
2.94E+10
50
0.01%
50
49
2.04E+10
1.91E+10
1.32E+09
<4%
2
A11-60
60
536
1
2.26E+10
50
0.01%
50
37.7
2.65E+10
2.40E+10
2.52E+09
<4%
2
A11-65
65
539
1
1.78E+10
50
0.01%
50
29.7
3.37E+10
2.93E+10
4.40E+09
<4%
2
A11-70
70
542
1
1.42E+10
50
0.01%
50
23.7
4.21E+10
3.49E+10
7.20E+09
<4%
2
A11-75
75
545
1
1.16E+10
50
0.01%
50
19.3
5.18E+10
4.06E+10
1.12E+10
<4%
2
A11-80
80
549
1
9.54E+09
50
0.01%
50
15.9
6.29E+10
4.61E+10
1.68E+10
<4%
2
A11-85
85
553
1
7.96E+09
50
0.01%
50
13.3
7.54E+10
5.11E+10
2.43E+10
<4%
2
A11-90
90
558
1
6.70E+09
50
0.01%
50
11.2
8.95E+10
5.52E+10
3.43E+10
<4%
2
A11-95
95
563
1
5.70E+09
50
0.01%
50
9.5
1.05E+11
5.81E+10
4.72E+10
<4%
2
A11-100
100
569
1
4.89E+09
50
0.01%
50
8.1
1.23E+11
5.91E+10
6.37E+10
<4%
2
A11-125
125
600
1
2.50E+09
50
0.01%
50
4.2
2.40E+11
1.29E+10
2.27E+11
<4%
2
A11-150
150
612
1
1.45E+09
50
0.01%
50
2.4
4.14E+11
-2.07E+11
6.21E+11
<4%
2

 

  Notes:
1
Size accuracy +/- 0.1 nm
2
Size accuracy +/- 2 nm
3
Peak SPR does not determine size for d<20 nm
Vol is 25mL, 100mL, 500mL, 1000mL
%PDI = Std Dev/Size
See Tech Note TN801 for definition of terms and method of analysis
All specs typical. May vary batch to batch. Exact values are measured for each batch
OD >= 1 for all sizes
Shape monodispersity (% spheres) > 99.9%
Solution is 18MEG DI water
Residual Chemicals < 0.1%

 

 

 

 

Part #
Diameter (nm)
Peak SPR (nm)
Optical Density (1cm)
NPS/ml
Wt. conc (mg/ml)
Wt. %
PPM
Molarity (pM)
Molar Ext. (M-1cm-1)
Absorption Molar Ext. (M-1cm-1)
Scattering Molar Ext. (M-1cm-1)
Size Dispersity %PDI
Notes
AC11-1.8
1.8
505-508
100
8.38E+16
5
0.50%
5000
1.40E+08
7.16E+05
7.16E+05
0.00E+00
<35%
1,3
AC11-2.2
2.2
505-508
100
4.59E+16
5
0.50%
5000
7.65E+07
1.31E+06
1.31E+06
0.00E+00
<25%
1,3
AC11-3
3
505-508
100
1.81E+16
5
0.50%
5000
3.02E+07
3.32E+06
3.32E+06
0.00E+00
<20%
1,3
AC11-4
4
505-508
100
7.64E+15
5
0.50%
5000
1.27E+07
7.86E+06
7.86E+06
0.00E+00
<20%
1,3
AC11-5
5
505-508
100
3.91E+15
5
0.50%
5000
6.52E+06
1.53E+07
1.53E+07
0.00E+00
<20%
2,3
AC11-10
10
514-520
100
4.89E+14
5
0.50%
5000
8.14E+05
1.23E+08
1.23E+08
0.00E+00
<15%
2,3
AC11-15
15
514-520
100
1.45E+14
5
0.50%
5000
2.41E+05
4.14E+08
4.14E+08
0.00E+00
<15%
2,3
AC11-20
20
514-520
100
6.11E+13
5
0.50%
5000
1.02E+05
9.82E+08
9.82E+08
0.00E+00
<10%
2,3
AC11-25
25
514-520
100
3.13E+13
5
0.50%
5000
5.21E+04
1.92E+09
1.92E+09
0.00E+00
<10%
2
AC11-30
30
523
100
1.81E+13
5
0.50%
5000
3.02E+04
3.32E+09
3.32E+09
0.00E+00
<6%
2
AC11-35
35
526
100
1.14E+13
5
0.50%
5000
1.90E+04
5.26E+09
5.26E+09
0.00E+00
<6%
2
AC11-40
40
527
100
7.64E+12
5
0.50%
5000
1.27E+04
7.86E+09
7.84E+09
2.28E+07
<4%
2
AC11-45
45
529
100
5.36E+12
5
0.50%
5000
8.94E+03
1.12E+10
1.10E+10
2.06E+08
<4%
2
AC11-50
50
531
100
3.91E+12
5
0.50%
5000
6.52E+03
1.53E+10
1.48E+10
5.97E+08
<4%
2
AC11-55
55
533
100
2.94E+12
5
0.50%
5000
4.90E+03
2.04E+10
1.91E+10
1.32E+09
<4%
2
AC11-60
60
536
100
2.26E+12
5
0.50%
5000
3.77E+03
2.65E+10
2.40E+10
2.52E+09
<4%
2
AC11-65
65
539
100
1.78E+12
5
0.50%
5000
2.97E+03
3.37E+10
2.93E+10
4.40E+09
<4%
2
AC11-70
70
542
100
1.42E+12
5
0.50%
5000
2.37E+03
4.21E+10
3.49E+10
7.20E+09
<4%
2
AC11-75
75
545
100
1.16E+12
5
0.50%
5000
1.93E+03
5.18E+10
4.06E+10
1.12E+10
<4%
2
AC11-80
80
549
100
9.54E+11
5
0.50%
5000
1.59E+03
6.29E+10
4.61E+10
1.68E+10
<4%
2
AC11-85
85
553
100
7.96E+11
5
0.50%
5000
1.33E+03
7.54E+10
5.11E+10
2.43E+10
<4%
2
AC11-90
90
558
100
6.70E+11
5
0.50%
5000
1.12E+03
8.95E+10
5.52E+10
3.43E+10
<4%
2
AC11-95
95
563
100
5.70E+11
5
0.50%
5000
949.9
1.05E+11
5.81E+10
4.72E+10
<4%
2
AC11-100
100
569
100
4.89E+11
5
0.50%
5000
814.5
1.23E+11
5.91E+10
6.37E+10
<4%
2
AC11-125
125
600
100
2.50E+11
5
0.50%
5000
417
2.40E+11
1.29E+10
2.27E+11
<4%
2
AC11-150
150
612
100
1.45E+11
5
0.50%
5000
241.3
4.14E+11
-2.07E+11
6.21E+11
<4%
2

 

  Notes:
1
Size accuracy +/- 0.1 nm
2
Size accuracy +/- 2 nm
3
Peak SPR does not determine size for d<20 nm
Vol is 25mL, 100mL, 500mL, 1000mL
%PDI = Std Dev/Size
See Tech Note TN801 for definition of terms and method of analysis
All specs typical. May vary batch to batch. Exact values are measured for each batch
OD >= 1 for all sizes
Shape monodispersity (% spheres) > 99.9%
Solution is 18MEG DI water
Residual Chemicals < 0.1%

 

 

CTABCTAB Structure

CTAB

Hexadecyltrimethylammonium bromide (CTAB) (C16H33)N(CH3)3Br, cetyltrimethylammonium bromide. As any surfactant, it forms micelles in aqueous solutions. At 303 K (30 °C) it forms micelles with aggregation number 75-120 (depending on method of determination, usually average ~95) and degree of ionization α (fractional charge) 0.2–0.1 (from low to high concentration). The standard constant of Br- counterion binding to the micelle at 303 K (30 °C) is K° ≈ 400.

 

citrate capped gold nanoparticle

Citrate Stabilized

 

PEI

Branched PEI

Polyethylenimine (PEI) or polyaziridine is a polymer with repeating unit composed of the amine group and two carbon aliphatic CH2CH2 spacer. Linear polyethyleneimines contain all secondary amines, in contrast to branched PEIs which contain primary, secondary and tertiary amino groups. 

 

PAA

Polyacrylic acid (PAA)

 

PAH 

Polyallylamine (PAH)  is a cationic polyeletrolyte.

 

PVP

Polyvinylpyrrolidone (PVP)

 

 

Composition

These bare spherical gold nanoparticles are shipped in  DI water with no measurable residual chemicals.

Custom Formulation

Diameters 1.8nm to 150nm.  Other sizes are special order.  Please contact us.

Quantity

This product is available in 25mL and larger. For orders larger than 1L, or for orders amounting over 10L per annum, please contact sales for quantity pricing.

Introductory Kits

For smaller evaluation volumes, two different kits are available, one with 25mL volume with a four bottle minimum and one with 1mL with an 8 bottle minimum.

Delivery

Standard sizes are in stock. Special order sizes are shipped in two weeks or less. All domestic shipments are sent Fed Ex Standard Overnight delivery, international Fed Ex Priority 2 day. No shipments on Fridays except for dried particles. Saturday shipping available for extra charge.

Functionalization

This product comes with different adsorbed ligands: our proprietary carboxylic acid, citrate, and adsorbed proprietary positive charged ligand, neutral charge and negative ligand, along with PEI, PAH, PAA, and PVP polymers.

Shelf Life/Storage Temperature

This product is guaranteed for six months and should be stored at 4 °C after opening. Care must be taken to only use sterile glassware when working with this product. For our dried particles, storage is room temperature with a shelf life of 1 year.

Toxicity

This product is known to be noncytotoxic. This product has been sterilized and is biological free.

The manufacturing method for these nanoparticles are based on our proprietary method. This invention allowed the first use of a reducing agent to be used at room temperature. Unlike citrate which is only a reducing agent at the boiling temperature of water - thereby quickly making non-monodisperse gold nanoparticles, our reducing agent works by slowing building nanoparticles from seed, atom by atom, over the course of up to hours. The result is a highly monodisperse product with unrivaled spherical shapes.

All of these "bare" particles are capped with ligands that are easily replaced with thiol and charge chemistries. We do not recommend using the carboxyl termination on our proprietary ligand as a conjugatable attachment.

  Nanopartz™Accurate™ Spherical Gold Nanoparticles Other Technologies
Monodispersity High (<2%) Low (>15%)
Size Accuracy High (+/-2nm) Low
Linewidths Narrow Broad
Storage lifetime Years 6 months at 4C
Ability to ligand exchange Easy More difficult

 

  • Highly accurate and monodisperse in size, shape, and batch to batch uniformity.
  • Accurate to +/- 2 nm in diameter.
  • Size monodispersity better than 4% CV for many sizes.
  • Greater than 99.9% spheres.
  • Carboxylic acid capping agent is reduced to < 0.1% without adverse effects to the spheres.
  • Extremely stable.  Shelf life is greater than one year.  May be stored at room temperature for extended periods.
  • The light scattering power of a 60 nm gold particle is equivalent to ~5 X 105 fluorescein molecules.
  • Accurate™ SGNPs do not photobleach.
  • Light scatter can be detected by the unaided eye at particle concentrations as low as 10-15 M (femtomolar) in suspension and as low as 0.005 particles/m2 on a transparent surface.
  • Individual gold nanoparticles can be seen by eye in an inexpensive student microscope with simple dark field illumination allowing for very sensitive and inexpensive particle counting assays.
  • Different sized particles scatter different colors of light and therefore can be used as multicolor multiplexed labels.
  • Facile conjugations allow for coating of antibodies, receptors, ligands, DNA without affecting their light scattering properties.
  • Slightly negatively charged (reduced aggregation).
  • Facile synthesis.  Gold chemistry is well known.
  • No known cytotoxicity.  Gold is FDA approved for rheumatoid arthritis.
  • Monodisperse shapes and sizes in production volumes satisfies high volume applications.
  • Smaller negative charge reduces aggregation.
  • Reduced number of additives improves binding to antibodies, receptors, ligands and DNA.
  • Monodisperse sizes and shapes leads to better standards for electron microscopy.
  • No photobleaching means better diagnostic labels with the ability to archive.
  • 105 better scattering power than fluorescein means lower limits of detection with simpler instrumentation.
  • More accurate sizing makes for better SPR matching for Surface Enhanced Raman Labels.
  • Monodisperse sizes and shapes leads to better Resonance Light Scattering labels in sensitivity and multiplexing.

 

image_0

Why are your spherical gold nanoparticles so much more monodisperse than conventional citrate stabilized gold nanoparticles?

Citrate stabilized gold nanoparticles are manufactured by combining sodium citrate and hydrogen tetrachloroaurate (gold) in water. In this combination, citrate not only acts as the capping agent, it also reduces the gold to a charge state that allows nanoparticles to form. However, citrate is only a reducing agent at the boiling point of water - so the solution must be boiled. Nanoparticle monodispersity is dependent on an even, homogeneous concentration of the chemical components in solution, and because boiling introduces heterogeneity into the process, the result is a very heterogeneous product.

Our capping agent is similar to citrate and is added to the hydrogen tetrachloroaurate in water like the citrate process. Additionally, by slowly adding gold over time, we can control the growth, shape, and monodispersity of the gold nanoparticles to within 2nm accuracies.

Why are your citrate stabilized gold nanoparticles so much more monodisperse than conventional gold nanoparticles?

We use our capping agent to manufacture the highly monodisperse gold nanoparticles and then ligand exchange our capping agent with citrate. Since the binding energy (k) for citrate is so much stronger than our capping agent, our capping agent is readily replaced.

How do you size your gold nanoparticles? Does the size include the capping agent?

We use three methods to specify our gold nanoparticles; TEM, UV VIS, and DLS. Each has its own advantages and disadvantages, and we use a weighted system to take advantage of each methods strengths. In the end, we place the strongest weight to the TEM method, particularly since we use samples sizes greater than 50 particles for each lot.

Do you really provide a TEM for my specific lot?

Yes, and not just for 5-10 particles, rather 50-100 are standard.

Why are your small gold nanoparticles colored? I have seen 2nm particles on other website that look as clear as water.

All gold nanoparticles absorb and/or scatter. If you can't see them, then they probably aren't there.

What is PDI?

PDI refers to polydispersity index and is equal to the standard deviation of the particle sizes divided by the average size.

Many companies claim better than 10% PDI using citrate. Is this possible?

We find that hard to believe.

Why is your shelf life time so much longer for your proprietary gold nanoparticles when compared to citrate stabilized gold nanoparticles?

As opposed to citrate, our capping agent is not a growth medium.

Are your proprietary gold nanoparticles interchangeable with citrate stabilized gold nanoparticles?

Yes. However, the user must be aware that in order to stabilize citrate gold nanoparticles, previous manufacturers used to add many stabilizing agents. Consequently for example to ionically attach ligands to gold nanoparticles required the chemist to "drive" the reaction by adding 10-1000 times greater concentrations of the ligand. This is no longer necessary with our gold nanoparticles.

 

"We were previously making our own gold nanoparticles using the commonly used technique of citrate reduction of Au(III). The colloids generated are broadly polydisperse, and we were concerned that our application of these particles in immuno-gold labeling of cells for optical coherence microscopy (OCM) would be utilizing only the large diameter tail of the distribution. We purchased the sampler package of NanoPartz gold spheres (30 nm, 50 nm, 70 nm, 90 nm) and examined each size carefully with dynamic light scattering, OCM, and spectrophotometry. Our measurements indicated diameters a couple nanometers larger than specifications (a result of measurements on the fully hydrated state?), and remarkable monodispersity - within specs. It is clear to us now that our early immuno-gold results were dominated by the largest diameter spheres of our early colloids. We are delighted by the NanoPartz monodisperse preparations and recommend them strongly!"

Dr. Richard C. Haskell 
Professor of Physics & Director of Physics Clinic 
Physics Department 
Harvey Mudd College



"The scientists at Nanopartz have developed a line of colloidal gold nanorods with extremely high monodispersity in size, shape, and mass. The surfactant layer is highly stable and readily displaced for biofunctionalization. In every test, in vitro and in vivo, these materials have exceeded our expectations."


Geoffrey A. von Maltzahn
NSF and Whitaker Graduate Fellow
Harvard-MIT Division of Health Sciences and Technology
Laboratory for Multiscale Regenerative Technologies

 

Cellular uptake and toxicity of gold nanoparticles in prostate cancer cells: a comparative study of rods and spheres

A Malugin, H Ghandehari - Journal of Applied Toxicology, 2010 - Wiley Online Library
... Plain, PEGylated spherical and PEGylated rod GNPs were obtained from Nanopartz (Salt Lake ...
Determining the size and shape dependence of gold nanoparticle uptake into mammalian cells. ...
4. TEM images of PC-3 cells incubated with plain spherical gold nanoparticles 30 nm ...

 

Geometry and surface characteristics of gold nanoparticles influence their biodistribution and uptake by macrophages

MM Janát-Amsbury, A Ray, CM Peterson… - European Journal of …, 2011 - Elsevier
... PEGylated gold nanoparticles (spherical particles of 50 nm in diameter and rod-shaped particles
with reported dimensions of 10 × 45 nm) were purchased from Nanopartz, Inc. (Loveland, CO,
USA). Before used, gold nanoparticle samples were incubated with cell culture ...

 

A simple millifluidic benchtop reactor system for the high-throughput synthesis and functionalization of gold nanoparticles with different sizes and shapes

SE Lohse, JR Eller, ST Sivapalan, MR Plews… - ACS …, 2013 - ACS Publications
... from several retailers in concentrations of >30 ppm (Sigma-Aldrich, Nanopartz, Nanoseedz, etc.). ...
for AuNRs in 2005 (which uses sodium borohydride, rather than spherical AuNP seeds ... batch
syntheses, even though the reactor permits synthesis of gold nanoparticles at higher ...

 

Negatively Charged Gold Nanoparticles Inhibit Alzheimer's Amyloid‐β Fibrillization, Induce Fibril Dissociation, and Mitigate Neurotoxicity

YH Liao, YJ Chang, Y Yoshiike, YC Chang, YR Chen - Small, 2012 - Wiley Online Library
... In this research, we have examined the effects of gold nanoparticles (AuNPs) on amyloids ... to inhibit
Aβ fibrillization and redirect Aβ forming fragmented fibrils and spherical oligomers. ... Bare,
amine-conjugated, and carboxyl-conjugated AuNPs were purchased from Nanopartz Inc. ...

 

NanoPen: dynamic, low-power, and light-actuated patterning of nanoparticles

A Jamshidi, SL Neale, K Yu, PJ Pauzauskie… - Nano …, 2009 - ACS Publications
... Figure 1c shows NanoPen immobilization and patterning of 90 nm diameter spherical gold
nanoparticles (purchased from Nanopartz Inc.(37 ... The stage is then manually transported leaving
a trace of gold nanoparticles in the illuminated area on the OET surface. ...

 

Off-resonance plasmonic enhanced femtosecond laser optoporation and transfection of cancer cells

J Baumgart, L Humbert, É Boulais, R Lachaine… - Biomaterials, 2012 - Elsevier
... The cells were incubated during 3–6 h with the AuNP (8 μg/ml, diameter 100 nm, Nanopartz)
in the culture medium at 37 °C and 5 ... In summary, the use of off-resonance spherical gold
nanoparticles allows to reduce the energy absorption by the nanoparticle, inhibiting its ...

 

Mechanistic heteroaggregation of gold nanoparticles in a wide range of solution chemistry

ARMN Afrooz, IA Khan, SM Hussain… - … science & technology, 2013 - ACS Publications
... that can determine aggregation behavior and enumerate aggregation mechanisms of gold
nanospheres (AuNSs ... stabilized AuNSs with 10 nm primary particle diameter were procured from
Nanopartz Inc ... Part a of Figure 1 shows spherical structures with angular features for some ...

 

Influence of transient environmental photothermal effects on optical scattering by gold nanoparticles

EY Lukianova-Hleb, DO Lapotko - Nano letters, 2009 - ACS Publications
... 10-A-100, Nanopartz, Salt Lake City, UT) and 250 nm (no. ... figure Figure 1. Experimental setup:
individual gold nanoparticles are coaxially illuminated by a pump laser pulse (532 nm), by a
continuous probe laser (633 nm), and also by a probe laser pulse (690 nm). ...