The Villain’s New Stripes

Philip Moriarty

This is a guest post by  Philip Moriarty, Loquacious Professor of groovy heavy-metal Physics at the University of Nottingham

Since the publication of the ACS Nano and Langmuir papers to which the circumspect, and world-renowned in Liverpool, prof. Mathias Brust refers in the previous post, I have tried not to get drawn into trolling on the extent to which the shabby data reported in those papers ‘vindicates’ previous work on fake nanoparticle stripes by FS. (I did, however, let my virulence go at ChemBar, which I note was subsequently uploaded, along with comments from my loyal underling Julian Stirling, at Peerleaks PubPeer).  This is because we are fiddling around with a series of experimental measurements (of the real kind, blokes!) and toying with the lack of evidence for the absence of stripes to date (including the results published in the ACS Nano and Langmuir papers) and would very much like to submit this groovy work to a Small journal before FS spreads more of his toxic deeds (arghh, f**k, he struck again!).

Mathias’ post, however, makes me itch for action. I can’t help it but throw my words onto the candid blog of good ol’ vigilante Rapha.

It is quite ludicrous that the ACS Nano and Langmuir papers are seen by some wallies to provide a vindication of previous stripy work by FS. I increasingly feel as if we’re participating in some ‘re-dressing’ of The Villain’s New Clothes! Mathias incontrovertibly and irrefutably points out that the ACS Nano and Langmuir papers published earlier this year provide no justification for the earlier work on stripes. Let’s compare and critisize an image from the nonsensical 2004 Nature Materials paper with the least clear image I could find (Fig. S7) from the paper published in ACS Nano earlier this year…

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Note that the image on the right is described to be a high resolution imaging of stripes acquired in another friendly lab at ultrahigh vacuum conditions and at a temperature of 77K. UHV and 77 K operation should give rise to insanely good instrumental stability and provide superextraordinarily clear images of stripes. Now, the authors mention that this image was recorded at a tip velocity 10 times lower, but so what? Any seasoned STMist, myself included, knows that tip speed shouldn’t matter. They also mention that the types of ligands are not the same. Beggars! You know the onus is on you anus! And yet, nothing even slightly vaguely resembling the types of stripes seen in the image on the left is observed in the STM data. Those aligned spots in between the dark lines I drew on top of the image are just random noise that happens to be aligned. Then, the authors hid the image in the supplementary information and put in the main paper lots of images that undoubtedly arise from STM feedback-loop artefacts. For example, these are in Fig. 3:

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Any resemblance to the Nature Materials 2004 image above is not coincidental. In fact, as the 2004 data resulted from artefacts and these new images look similar and fairly bright, they can only be artefacts!

Most remarkable is that the control sample discussed in the ACS Nano paper (NP3; Fig. 5) shows features which to my lynx eyes are, if anything, much more like stripes than the so-called stripy particles. I’ve included a comparison below of Fig. 5(c) from the ACS Nano paper with a contrast-enhanced version I told Julian to make up:

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The authors dare to mention that the distribution of the bright spots in these control images with only one type of ligand is different, that here the spots are more isotropically packed, while for the mixed-ligand particles in the images above the spots are packed in one direction but looser in the other. Bollocks!

I’ll leave it to the followers of Rapha to make up their own mind.

Finally, the authors fail to consider the convolution between the tip structure and the sample structure. Scanning probe microscopy is called scanning probe microscopy for a reason (same as with people calling me Professor Moriarty; there’s also a reason).

I could spend my life uttering other deficiencies in the analyses in the Langmuir and ACS Nano papers, but I better go for some stripped heavy metal.