Dimensional measurements of nanoparticles are extremely important for their applications in a diverse range of fields. The unique properties of nanoparticles depend strongly on their size, so it’s extremely important to be able to characterize, and control nanoparticle sizes. For example, an extremely small change in the dimension of a quantum dot nanoparticle will give rise to dramatically different photoluminescence characteristics. in the case of metallic nanoparticles, the size of the particle will alter light absorption and scattering properties, which are highly important for many applications, including in disease diagnosis and therapy (1). Many other properties depend on nanoparticle size, including magnetic and mechanical properties, interactions with cells and tissues, etc. The shape of nanoparticles also has a strong effect on these properties.
Thus, in nanoscience, it is crucial to have a tool that can simply characterise particles size and shape of nanoparticles, irrespective of the material of which they are composed, with sub-nanometer resolution. The figure below shows AFM imaging of a variety of nanoparticle types.
AFM fulfils these requirements, z-axis (height) measurements in AFM can be accurate to within 0.1 nm. AFM also has several other advantages for characterisation of nanoparticles:
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Wednesday was a beautiful sunny day so fortunately all the students had either the morning or afternoon off to make the most of the trip to the beautiful city of Porto. The practical classes went really well, and some of the images obtained by the students can be observed on this page. We always run a “best image” competition, so the students are extra-motivated to collect great AFM data. The results of this competition will be run very shortly. I was particularly impressed that within a classroom environment, with four people around, the students were able to image DNA; getting decent images of structure that are less than one nanometre in height!
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This website was taken offline on Wednesday 27th April. The reason was that the site had been hacked, was occasionally redirecting users to other websites. I have removed the vulnerabilities, have the site fully functional. The site was down for a total of 5 days.
If you ever are redirected to another site from this one (without clicking on an appropriate link), or see anything wrong with the site, please let me know by filling the contact form.
Thank you for your patience, and apologies if you found something here you should not have!
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As usual, during our AFM training course , we ran an image competition, challenging the students to submit images they had acquired or processed during the course.
This year, the standard was very high, and we could not decide between two of the entries, so two prizes have been awarded.
The overall prize goes to the image below of E. coli bacteria which was produced by Dr. Cassandra Terry of UCL, London. The processing on this makes was excellent!
We could not go without giving a prize to this image of double-stranded DNA molecules obtained by Dr. Elin Moe of ITQB, Lisbon. This image, below, won our technical merit prize. Acquiring such an image in your first session with an AFM is impressive!
Congratulations to both, your prizes will be with you soon!
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