Often my conducting tips become contaminated whilst measuring IV's of my monolayer using conducting probe AFM. Rather than taking the probes to UVOX or plasma asher (as others have suggested), is there an efficient way of removing/cleaning contamination from the probes in situ?
Some have suggested applying high bias to the conductive substrate, but others say that this just causes more permanent damage/contamination (because my monolayer covers the whole of my conducting substrate). Others have suggested that high bias actually removes the metal coating. Does anyone have a more reliable protocol to clean a conducting tip in situ?
I think, it is impossible to effective clean the tip in situ.
If the conductive coating is Au or Pt, the best way is use the Piranha solution (H2SO4 + H2O2, 3:1). Mix the reagents and incubate the probe for 2-3 min.
Good luck!
I did it once increasing the PID parameters and measuring, but what kind of tip you have? coated? because that technique is not useful because you will remove the metal from the tip.
Another thing that you can try is measuring a very flat surface, and the piranha idea is a very good one.
Best regards from México.
Of course anyone can use FIB to remove contaminations from the tip and it's shape modification, but it depend on what kind of probe You have and how much time you want to spend on it? If eg. TT from Veeco/Bruker (PSM) made of tungsten it is easy to make/etch another one using electrochemical methods. In case of using coated probes it is possible to clean it with fast scanning flat surface. Usually some contamination will drop out because of friction and or electrostatic charge between moving elements. Another method - which I did not try - is to heat tips with quartz lamp. I didnt try to use piranha as Denis suggested, but looks it is not bad idea. Anyway, if I were You i would like to try fast (really fast, when image acquiring is not possible) first.
Hope it helps.
The following discussion seems of some possible interest concerning to your query; being, however, about cleaning a gold coated AFM cantilever from glue: https://www.researchgate.net/post/What_is_the_best_organic_solvent_for_cleaning_the_gold_coated_cantilever
Ben one way that I have gone about cleaning a conductive AFM tip is by scanning an highly-conductive "standard". Scanning this standard with a small bias (i.e., constant-bias cAFM scanning in contact mode) usually generates enough Joule heating/friction near the tip to remove contaminants I have come across (in other words, watch the raw current window as you scan this standard - at some point you will see the "recovery" point). After scanning that standard a few times in a few directions, I can then return to my sample of interest.
For example, solvent and oxygen plasma-cleaned indium tin oxide on glass works quite well as a standard. I actually usually would just "co-mount" this ITO standard with my sample of interest on the same silver-pasted AFM puck for ease of access (i.e., I could return to the ITO whenever I was losing confidence in the AFM tip's status).
This technique worked well with conductive tips that were "solid" conductive tips (e.g., doped diamond or platinum) as opposed to coatings (which may simply just wear off - and conductivity is lost irreversibly).
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