Precision Rectifier Circuit to detect peaks
C2 is too big for this sort of application. The OPA350 is only capable of 80mA  of output current and it takes a long time to charge the 680uF cap. You then also need then a very small R3 value to discharge it rapidly between peaks. 

Set C2 at about 2uF and R3=100k Ohm  

That will give you reasonable peak capture and a decay time in the 200mS range. If you need to make this voltage available elsewhere you could add another OPA350 as a buffer.







simulate this circuit &ndash; Schematic created using CircuitLab