Electrodes for "Plant Singing" Sonic Arts

Hi!
I'm looking for the best electrodes, compatible with Arduino, to make something like this
for my Master's Degree thesis:

or this Plant Sounds - YouTube

In fact it would be a matter of measuring the capacitive variations of the plant and sending the signal being processed to max / msp or similar.

Has anyone already had similar experiences?
I have found electrodes for ECG and muscle measurements for humans, can they be okay?

( for example Kit modulo ecg AD8232 per elettrocardiogramma cardiofrequenzimetro arduino 7426835677706 | eBay )

Thanks a lot to everyone has good advices.