Talk:Colloidal gold

message: There seems to be a mini edit-war breaking out over the use of micron versus micrometre and M versus mol.  Am I right in thinking that the latter in each case is technically more correct that the former?  Specifically, micron is an old and deprecated (although common) alternative for micrometre, and M actually refers to the molarity of a solution rather than one mole.  -- ALoan (Talk) 11:09, 11 Aug 2004 (UTC)
thread_title: Units

message: I removed the entire section of external links (two of them) here  - they don't seem to fit into the theme of the artice content as it exists at the moment. Thoughts? What would be really nice would be an external link to polymerization reactions conducted on colloidal gold particles. I'll see if I can find something like that. --HappyCamper 17:47, 25 May 2006 (UTC)
thread_title:  External links 

message: Removed section again as it is not sourced to a reliable peer reviewed source, rather to A Meridian Institute website. Wiki is not for the promotion of quackery. --Vsmith 12:50, 3 January 2007 (UTC)
replies: text: Followup:  I've gone ahead and added a section for this and contributed quite a few government and medical-journal sources for all of the information that I added.  No quackery here (as if the government never participates in such--LOL).  Yosemite1967 23:10, 27 August 2007 (UTC)
thread_title:  "Health benefits" 

message: I remember that in the novel Cancer Ward by Solzhenitsyn, one of the patients needs colloidal gold for some test or treatment. What could it be? Sergivs-en 08:25, 2 May 2007 (UTC)
thread_title:  Cancer Ward 

message: We need a reference that nanoparticle gold is the same as colloidal gold, preferrably in the reference itself, or it might be WP:SYN.  As it stands, there's clearly (although this is WP:OR on my part) a difference between chelated gold (sometimes also called colloidal gold, although there's only one gold atom per structure) and structures containg a few to a few hundred gold atoms coated with some sort of ionic substance.  — Arthur Rubin |  (talk) 19:21, 23 September 2007 (UTC)
replies: text: OK, withdrawing.  — Arthur Rubin |  (talk) 21:13, 24 September 2007 (UTC)
thread_title:  Dubious 

message: Are gold colloids/nanoparticles the "active" ingredient in the ancient pigment Purple of Cassius?  If so, should Purple of Cassius redirect to this page?  —Preceding unsigned comment added by Chem web7 (talk • contribs) 03:02, 23 January 2009 (UTC)
thread_title:  Purple of Cassius 

message: sodium hypochlorite (concentration 15% - bleach sodium) + hydrochloric acid (concentration 5% - muriatic acid) + gold dust (filings of gold) --- 48-56 h ---> Gold chloride (yellow-gold solution) HAZARD! Chlorine gas !!!! 
Gold chloride (yellow-gold solution) + sodium bicarbonate ---> precipitated eventual copper carbonate (blue - green), Gold chloride remains in solution (yellow-gold), sodium bicarbonate acts as pH Buffer System and reduce acidity (strong effervescence !)
Gold chloride solution + saccharose (sucrose) or glucose --- 24-48h ---> Colloidal Gold (purple shades) or "purple of Cassius"
try it!  —Preceding unsigned comment added by 82.50.35.58 (talk) 16:50, 4 April 2009 (UTC)
thread_title:  A simple method for the production of colloidal gold 

message: There are no reference to the method of making the colloidal gold.  There is a paper from 1951 I would hope someone could find it. --Saxophonemn (talk) 18:44, 16 July 2009 (UTC)
thread_title:  References for Method 

message: On 22-May-2009 two peacock tags were added to the following text:
:Known since ancient times, the synthesis of colloidal gold was originally used as a method of staining glass. Modern scientific evaluation of colloidal gold did not begin until Michael Faraday's work of the 1850s. V. R. Reddy, "Gold Nanoparticles: Synthesis and Applications" 2006, 1791, and references thereinMichael Faraday, Philosophical Transactions of the Royal Society, London, 1857 Due to the unique optical, electronic, and molecular-recognition properties of gold nanoparticles, they are the subject of substantial research, with applications in a wide variety of areas, including electronics, nanotechnology,Paul Mulvaney, University of Melbourne, The beauty and elegance of Nanocrystals, Use since Roman timesC. N. Ramachandra Rao, Giridhar U. Kulkarni, P. John Thomasa, Peter P. Edwards, Metal nanoparticles and their assemblies, Chem. Soc. Rev., 2000, 29, 27-35. (on-line here; mentions Cassius and Kunchel) and the synthesis of novel  materials with unique properties. 
I disagree with these tags and pending discussion will remove them after a reasonable amount of time. My disagreement is as follows:
1. The word "novel" is a precise term that means "of recent origin or introduction" and "of a kind not seen before" . This is not a peacock term, and in fact I would go so far as to say that a synonymous but more verbose phrase like "previously unknown" would be.
2. The phrase "unique properties" is also a precise term meaning "alone", "sole", and "unlike others". I might agree to this needing a citation to affirm the uniqueness quality but it is again not a peacock term. 
66.102.199.179 (talk) 03:49, 17 October 2009 (UTC)
thread_title:  Peacock Tags 

message: The Wiki article noted somewhere that the colour of the gold sol is relative to the concentration of the gold sol in solution, it should be noted that the colour of the sol is more reliant on the size of the gold sol particles than the concentration of the sol.  —Preceding unsigned comment added by 134.148.4.14 (talk) 01:25, 9 August 2010 (UTC)
thread_title: Colloidal gold colour

message: I'm a simple college student. I'm editing this page to work towards my final paper. Though, before I do add anything to this, I wanted to ask if there is any talk on the page about the therapeutic processes for gold particles. From what I have read, there isn't a paragraph or any little snippet about it. Is it alright if I add some of the stuff I have found? PMcShurley (talk) 19:34, 12 November 2009 (UTC)
replies: text: Please read WP:OR. It can be added if it has already been published in a reliable, peer-reviewed journal or book or other reliable source, although adding it yourself may be risky (see WP:COI). If this is your own ongoing, unpublished research, it should not be added here until it has been first published elsewhere.—Tetracube (talk) 19:54, 12 November 2009 (UTC)
thread_title: Therapeutic processes

message: This whole section is extremely esoteric, minutia, relevant only because very current at the time of posting.  I'm axing it.  —Preceding unsigned comment added by 207.237.243.185 (talk) 06:59, 15 February 2010 (UTC)
thread_title: "Current Research"

message: In science the main thing colloidal gold is used for is as a contrast agent in biological electron microscopy!  This was already true when I took undergrad cell-biology in 1986.  Your article was badly incomplete without mentioning this, as it mentions much less-important uses of colloidal gold.  I have begun a section on colloidal gold in biological electron microscopy for you with three references (one from 1977 and two from the Procedings of the National Academy of Science) but there's loads of examples and derivatives of colloidal gold used to label particular tissues and organelles for electron microscopy.
UPDATE: added more references  —Preceding unsigned comment added by 207.237.243.185 (talk) 04:49, 18 February 2010 (UTC)
replies: text: With new innovations that is going to be an outdated use. :) John Riemann Soong (talk) 14:32, 8 February 2011 (UTC)
thread_title: The main thing it's used for!

message: A clearly COI editor remove "nanogold" from the lede, as being trademarked.  That might be a valid reason for deletion, except the redirect from Nanogold would also need to be deleted, and reference 30 refers to "nanogold", without any evidence that it's a trademark, at least in the abstract.  — Arthur Rubin  (talk) 19:25, 6 October 2010 (UTC)
replies: text: Even if 'nanogold' is trademarked, that is no reason to remove it's mention... Trademarking does not make it illegal to refer to the product in an article, we don't even need to add ™ (per MOS:TM). For examples see any company page (e.g. Nike) Jebus989✰ 11:39, 2 May 2011 (UTC)
thread_title:  Nanogold 

message: Anybody else came across this before??
Previous work has been done in our laboratory with regards to the creation of AuNP's in solution using Nd:YAG laser ablation
It's a very simple method of creation, with surface plasmon resonance (SPR) being seen even after 5mins of ablating at low powers using fundamental 1064nm output
further ablation with 532nm output (which is very close to the SPR of 520ish nm) results in a very uniform spread of AuNP's with diameter of 1-5nm
I can dig up a reference for discussion here if warranted
Usherly (talk) 11:11, 2 May 2011 (UTC)
thread_title:  Laser Ablation 

message: The first sentence talks about "usually water" as the working fluid. Well, to provide a sense of completeness I can provide something else: colloidal gold can be dissolved in various molten glasses to form a brilliant scarlet glaze (on pottery). I even have some images of this.
But is this enough of a referenced source? All of this information is from my friend who runs a pottery business and buys a commercial glaze that arrives in a bottle labelled "Colloidal Gold Glaze". Now is that enough of a reference, or is that OR?
Old_Wombat (talk) 06:51, 24 July 2011 (UTC)
replies: text: Interesting and the stuff does exist, so the addition with images would be good - but your friend and the bottle label wouldn't be WP:RS, so would need to find a non-commercial source to support. Vsmith (talk) 14:45, 24 July 2011 (UTC)

text: Quick google search provided  and  book links which should work (the books as refs not the google search links). Vsmith (talk) 14:49, 24 July 2011 (UTC)
thread_title:  Colloidal gold in something else. 

message: I removed the part as well as the following ref link http://www.ncbi.nlm.nih.gov/sites/entrez?Cmd=ShowDetailView&TermToSearch=17381835 which was about "veterinary acupuncturists" implanting gold BEADS in dogs. This form of gold is NOT colloidal, the study precisely states beads and not any solution containing colloidal gold in any manner, nor any gold salt, only BEADS. A bead being a macro sized sphere of gold, measurable in tenths of inches or millimiters. This kind of alternate medicine link should be rather put in the wikipedia article about GOLD in general, not in the Colloidal Gold article.
89.82.152.110 (talk) 01:52, 9 January 2012 (UTC)
replies: text: Seems like some people have trouble reading or understanding here. Edits by 89.82.152.110 have been reverted, why?? Colloidal gold is not "gold beads" as referred to in the journal (see link). 89.82.152.110 is right when he says that colloidal gold and macro sized gold should not be on this colloidal gold wikipedia page. Arthur Rubin, who erased edits by 89.82.152.110 , should read more about differences between colloidal metals and their solid human-scale counterpart : silver salts reduce to elemental colloidal metal in human teeth in the affection called argyrism for example, while implanting a solid piece of pure silver under the skin would not lead to have blue-grey teeth.In the case of gold, colloidal gold forming after injection of gold salts leads to renal failure (due to formation of colloidal gold) but elemental gold in non-microscopic sizes does not react with body fluids if implanted. Hypothetic health "benefits" from such sized pieces of gold implanted under the skin have nothing to do with colloidal gold and or gold salts effects. 82.240.163.245 (talk) 19:51, 11 January 2012 (UTC)
replies: text: I didn't say gold beads were colloidal gold; I said they were related to colloidal gold.  And you seem to be saying that the gold bead study is wrong.  Absurd, isn't it.  — Arthur Rubin  (talk) 20:17, 12 January 2012 (UTC)
replies: text: Let's face it, your purpose is to confuse people by putting a ref about MACRO SIZED GOLD BEADS in the COLLOIDAL GOLD article. Why you insist is a mystery, perhaps you are yourself a "veterinary acupuncturist" ! The wikipedia article is not about "health effects of gold" it's about the health effects of COLLOIDAL GOLD (and related salts that would eventually be reduced to colloidal gold in vivo). If you have any ref pertaining to the -claimed- effects of gold beads in an obscure and isolated research paper, then post it in the wikipedia article about GOLD, not COLLOIDAL GOLD. To show you how wrong your point of view is, simply imagine SILICA and SILICA FUME. THe first will not react with body fluids  while the second, if inhaled for example, will clog your lungs and eventually initiate tumors like many nano sized particles would . Silica powder coats the intestines while a macrosized silica sphere would only pass through unmodified. Gold isn't glass but my point is you cannot talk about the effects of "macroscopic" sized material in the colloidal dedicated article, unless you compare both aspects meticulously by pointing out the differences (when it's neutral and when it starts being reactive to the human body (or animals, plants ...) . In regards to these considerations, your veterinary acupuncture ref about macro sized gold beads is abolutely NOT valid (even though you consider beads "micro" sized, due to their dimeter of approximately 2mm , which is ABSOLUTELY NOT related to colloidal gold. In one word, "micro" in the mouth of an acupuncturist is worth nil).82.240.163.245 (talk) 14:37, 14 January 2012 (UTC)
thread_title: Gold "beads" study

message: Correct me if I'm wrong, but not a single one of the studies on the health risks actually mentions colloidal gold, they're all talking about gold salts. Why would they be included in this article? It's very misleading. --108.160.47.85 (talk) 23:36, 10 November 2012 (UTC)
replies: text: You are right.  I deleted the section.Desoto10 (talk) 04:13, 7 June 2013 (UTC)
replies: text: Actually, I transferred the entire section, with a few tweaks, over to the Gold salts article where it fits.Desoto10 (talk) 18:34, 7 June 2013 (UTC)
thread_title:  Health and medical applications 

message: The 3-4 topics in this section are all in the preliminary animal study stage.  Maybe a better heading would be Medical Research or something similar. Desoto10 (talk) 03:14, 14 August 2013 (UTC)
thread_title:  Health and medical applications Part II 

message: Several synthesis methods are listed with their own paragraphs. They are cited correctly, but their merit relative to the Frens and Brust methods has been challenged by several users. Guidelines could be useful in this regard. A study in chemistry could be considered useful if cited at least 50-100 times in ~5 years. If few citations happen, the method may not work or does not improve on prior art. If the method is actively cited, it should be considered as worthy of listing. Also, the absolute number of citations is not a valid comparison for a new study vs. one that is decades old. 
NanoProf (talk) 18:17, 8 October 2013 (UTC)
thread_title: Synthesis Methods

message: The section on green chemistry based methods is disproportionate and comes across merely as green POV. The idea that colloidal gold can be made with Darjeeling tea leaves is briefly amusing, but scientifically risible, and is never going to run in any serious scientific or industrial manufacturing context. (If I am wrong and green, tea-based methods are the way to go, please provide details and a citable source). Apart from gold chloride, colloidal gold is often made from completely edible and environmentally safe reducing agents, such as citric acid, ascorbic acid (vitamin C) and distilled water as the solvent.  There is therefore no case for using a less toxic solvent, and the case for using chemically undefined "green" ingredients is therefore obscure.  I suggest deletion of this section. Plantsurfer 12:18, 26 March 2015 (UTC)
replies: text: Two years, and not a peep from anyone about this, for or against. To repeat, no case is made here to support the need for a "green" technology for gold nanoparticle production.  This section is occupying space for no good reason. Unless a case for its retention is made then it is Going, going, go .  . . . Plantsurfer 11:55, 21 February 2017 (UTC)
thread_title: Green chemistry based methods

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thread_title:  External links modified 

message: There's been some discussion at WT:CHEMICALS about splitting this article into Colloidal gold and Gold nanoparticle articles.  The two are overlapping but are not the same: one could have a colloid that is not composed of nanoparticles (because the particles are too large), and one can have nanoparticles that are not a colloid (because they are not in suspension, for example if they are in powder form).
As written it seems that the History and Physical properties sections are mostly about colloids while the rest is mostly about nanoparticles.  But the whole article has such problems with using primary sources, may of which are outdated—especially since a significant portion of the article falls under WP:MEDRS—that it might be better to just start over with a new Gold nanoparticle article.  John P. Sadowski (NIOSH) (talk) 03:37, 30 August 2017 (UTC)
thread_title:  Colloidal gold vs. gold nanoparticle 

message: Chemical Abstracts has 14,298 references on "colloidal gold", since 2014, there are 3188, including 63 reviews.  If the concept of colloidal gold is searched, one retrieves 503,459 references.  Half a million.--Smokefoot (talk) 18:47, 17 July 2019 (UTC)
thread_title: CAS report: about 1-2 papers per day on "colloidal gold"