I am working in the current range of about 0 - 500 nA.
I am seeking a Limit of Detection of 10-20 nA upon making analyte additions using the Amperometric + AD5940main firmware.
Does anybody have any suggestions on how to achieve the maximum sensitivity with as little noise? As of now, I am using the max gain (512k) with rload of 3k6. I have enabled I believe notch filters in the Amperometric.c file but if someone can point to exactly where in the code that is that would be great verification that I did it correctly. I'm afraid a gain of 512k isn't sufficient and perhaps an external TIA will be needed assuming the current range is still regarded as 0.9V/RTIA.
But if there is anything else I can do to improve the sensitivity of the AD5940 please let me know.