Circuit for the detection of uA current

[DuftDerBlumen]

Hello,

I need to measure the amount of current produced by the moving electrons resulting from the oxidation of glucose to gluconolactone catalyzed by glucose oxidase (This amount should be in the uA-range) do you know if there is a circuit to detect this current?

Thank you

 

[karesz]

Hi,
Check pls by Keithley: "PicoamMeter"...
K.
P.S.: Can you apply some higher voltages & do you wish self backed circuit or an equipment to buy pls?

 

[ZigaM]

Hello.

Maybe you can use transimpedance amplifier. For example OPA381

https://focus.ti.com/lit/ds/symlink/opa2381.pdf

In this datasheet you will find some usefull schematics for your design.

 

[karesz]

Hi
For some ideas refer pls to "fig. 100":
**broken link removed**
Biologically closed electric circuits_clinical, experimental and ... **broken link removed**
K.

 

[karesz]

If you will scale the circuit of Fig.8: ie to 1MOhm instead of 1GOhm=1V/uA, but it will have much higher speed as the typical circuits (i.e. from OPA 2381 datasheet)...
K.

 

[DuftDerBlumen]

Many many thanks for all your reply, it was really very helpful.
Best regards,
Chadha

 

[karesz]

Hi Duft...
What are you decided/selected to realize pls?
K.

 

[ZigaM]

If you will scale the circuit of Fig.8: ie to 1MOhm instead of 1GOhm=1V/uA, but it will have much higher speed as the typical circuits (i.e. from OPA 2381 datasheet)...
K.

Hi,

I just give example of the amplifier. If you need greater bandwidh you simply choose another trans-amp.

But you should be careful, because high bandwidh is not good when you don't need it.