Depends on your budget, but the JouleScope [1] can measure down to half a nanoamp. Absolutely amazing piece of kit for the price ($1,000). They also have a pyt

Depends on your budget, but the JouleScope [1] can measure down to half a nanoamp. Absolutely amazing piece of kit for the price ($1,000). They also have a python library [2] so you can do lots of stuff inside Jupyter. [1] - https://www.joulescope.com/ https://www.joulescope.com/ [2] - https://joulescope.readthedocs.io/en/latest/ https://joulescope.readthedocs.io/en/latest/