Find PI's main publications Nowadays, people in biology make huge collaborations, so of course they're all having loads of publications.

Therefore, I was wondering if there is a way, on Google Scholar or on other sites, to filter for a PI's publications as last author. That would be really helpful!

Thanks in advance
I don't think that it is possible to search author order in Web of Science, Scopus or GS, directly from their web sites. However, if you get access to a database built on e.g. raw WoS data it is possible (author order is preserved there). 

In your case the easiest solution is probably to export all publications where your PI is a co-author from e.g. WoS or Scopus and process the data in excel/R/whatever, to extract the last author name in the author string.

In Excel you can e.g. use this on the author field (AU) from a WoS export to get the last author:

=TRIM(RIGHT(SUBSTITUTE(A2,";",REPT(" ",LEN(A2))),LEN(A2)))


This can then be used to filter out the publications with PI as last author, maybe after some more cleaning for e.g. first initial.

Long author strings (which is partially what your question is dealing with, i.e. long author lists) may cause character number overflow though (excel cells can only hold a certain number of characters), so you might want to run e.g. =RIGHT(A1;100) on the AU field first to decrease its size, before running the other function to get the last name.