Fluorophore Labeled Gold Nanoparticles for Cell Transfection and Nuclei Uptake

Nanopartz has developed a gold nanoparticle construct that has shown efficient cell transfection and uptake into cell nuclei, specifically targeting PML bodies. These gold nanoparticles have diameters from 1.8nm to 3nm and can be imaged by either confocal fluorescence or electron microscopy. Most importantly, they are large enough that they don't need to be grown through silver or gold growth methods after the fact as post treatments are known to destroy cell ultrastructure. These products show the potential for drug and oligo delivery to cell nuclei. 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 one concentration, OD=25 (1.25mg/mL) in 18MEG DI water (default), purified of residual reactants to <0.1%.

In the Product List Tab below, click on the product part number for current lot specification sheets.



Part #
Diameter (nm)
Peak SPR Wavelength (nm)
Molarity (pM)
Molar Ext. (M-1cm-1)
Absorption Molar Ext. (M-1cm-1)
Scattering Molar Ext. (M-1cm-1)
Size Dispersity %PDI
Size Accuracy (+/- nm)


Optical Density >= 25
Wt conc = 1.25mg/mL
Wt % = 0.125%
ppm =1250
%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
Shape monodispersity (% spheres) > 99.9%
Solution is 18MEG DI water
Residual Chemicals < 0.1%



Fab Fragment Goat Anti-Mouse IgG (H+L)
Fab Fragment Goat Anti-Human IgG (H+L)
Fab Fragment Goat Anti-Rabbit IgG (H+L)
Neut Neutravidin


Wavelength Name Excitation (nm) Emission (nm) Ext. Coef QY
405 AF405 402 421    
  Dy405 400 420    
488 FITC 494 518 70000  
  Dy488 493 518 70000  
  AF488 490 525    
514 NPZ514 520 540    
532 Rhodamine 535 575    
550 Cy3 555 570 150000 0.31
  Dy550 562 576    
  AF555 555 580    
600 Cy3.5 591 604 116000 0.35
  Dy594 593 618    
  AF594 590 617    
  Texas Red 592 614    
650 Cy5 646 662 250000 0.2
  Dy 650 652 672    
  AF647 650 665    




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

Custom Formulation

Diameters 1.8nm to 3nm.  Larger sizes may reduce nuclear uptake. Please contact us.


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

Introductory Kits

None are currently available.


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.


This product comes with a number of Frag' IgG functionalizations with a complete range of fluorophore choices.

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.


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


This product is sterilized.


Every order comes with a Certification of Analysis that includes the following information. We use calibration traceable:

UV-VIS (Agilent 8453) for extinction and concentration measurements

NIR (Cary 500) for NIR extinction and concentration measurements

DLS (Malvern Nano ZS) for zeta potential measurement

ICP-MS (Varian 820-MS) for gold mass measurements

TEM (Phillips CM-100 100KV) for sizing

Spherical Gold Nanoparticles UV VIS


What are Nuclear PML bodies?

PML nuclear bodies (NBs) are spheres of 0.1–1.0 µm in diameter found in most cell-lines and many tissues. They belong to the nuclear matrix, an ill-defined super-structure of the nucleus proposed to anchor and regulate many nuclear functions, including DNA replication, transcription, or epigenetic silencing. The PML protein is the key organizer of these domains that recruits an ever-growing number of proteins, whose only common known feature to date is their ability to be sumoylated. PML and NBs were proposed to fine-tune a wide variety of processes, through facilitation of partner protein posttranslational modifications resulting in partner sequestration, activation, or degradation. Several NBs subtypes have been defined on morphological bases, which all contain an electron-dense shell and an inner core.

Why are you able to get high efficiency nuclei uptake with such large gold nanoparticles?

Two reasons: 1) the monodispersity of our gold nanoparticles and 2) the ligand design construct. Our ligand design has reduced the overall size of the construct, making it more efficient at nucleus uptake.

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 OD?

Optical Density (OD) is measured by UV-VIS. An Optical Density OD=1 corresponds to a transmission of 10% through a 1cm cuvette. Optical Density is a nice unit to use since Optical Densities correlate linearly to concentration. So an Optical Density of 1.2 is equal to 1.2 times the concentration of a gold nanoparticle solution that has an Optical Density of 1. We use OD and concentration interchangingly as it is easier to refer to a solution of OD=1 rather than 2.35e12 nanoparticles. For all spheres up to 200nm, OD=1 does refer to 0.05mg/mL.

What is PDI?

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

"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). ...


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.
    • Monodisperse sizes and shapes leads to better standards for electron microscopy and other diagnostics.
  • Accurate to +/- 2 nm in diameter.
    • More accurate sizing makes for better SPR matching for Surface Enhanced Raman Labels.
  • Size monodispersity better than 4% CV for many sizes.
    • Monodisperse sizes and shapes leads to better Resonance Light Scattering labels in sensitivity and multiplexing
  • Greater than 99.9% spheres.
  • Carboxylic acid capping agent is reduced to < 0.1% without adverse effects to the spheres.
    • Reduced number of additives improves binding to antibodies, receptors, ligands and DNA.
  • 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.
    • No photobleaching means better diagnostic labels with the ability to archive.
  • 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.
    • 105 better scattering power than fluorescein means lower limits of detection with simpler instrumentation.
  • 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

Example part number is PNU11-1.8-488-DIH-50-1-CS-EP where:

PCU11 - Product family number for Nanopartz Cell Uptake

10 - Sphere diameter in nanometers.

488 - FITC Fluorophore

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

50 - Optical Density, in this case OD=50

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

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

EP - Endotoxin Purified - The product is endotoxin purified and certified.

How to Order

Ordering by scrolling down and selecting the options from the selection below.


» PNU- Cell Nuclei Uptake
Conjugated Spherical Gold Nanoparticles Nuclei Uptake
Conjugated Spherical Gold Nanoparticles Nuclei Uptake
Part Number Format: PNU11-(DIAMETER)-(FLUOROPHORE)-(FUNCTIONALIZATION)-(OD)-(VOL)-(CS)-(EP)-(NR); where Diameter = 1.8, 2.2, or 3nm. Fluorophore is from 405nm to 680nm. Functionalization = GAMG, GARG, GAHG, or Neutravidin. OD=25. Volume = 1 or 5mL, CS= Optional Certified Sterilized, EP = Optional Endotoxin Purified, NR = Optional Non reactive Control. Sample Part Number is PNU11-1.8-FITC-GAMG-25-1.
Gold Nanoparticles Diameter (nm)
See "Functionalization and Fluorophore Information" in tab above for more detailed information about the fluorophore choices
GAMG - Fab Fragment Goat Anti-Mouse IgG (H+L)
GARG - Fab Fragment Goat Anti-Rabbit IgG (H+L)
GAHG - Fab Fragment Goat Anti-Human IgG (H+L)
NEUT - Neutravidin
Optical Density (OD 25=1.25mg)