This amplifier for electrometer can work with currents of 0.1 pA in a band of 1 Hz. The circuit is from NASA in a publication of the 60s. Transistors are general purpose types.
This circuit was found in a 1980s US publication. There may be some difficulty in obtaining the...
May 2017 - The new 36V TLVx171 Series of General Purpose Operational Amplifiers from Texas...
We found this circuit in a Popular Electronics of the 80's. The circuit can be used to drive...