Is there any method?

This is not an exact answer to the question.

The literature so far examines the phytochelatin synthase enzyme activity, or phytochelatin (PC) isolation & determination via an analytical device (i.e: HPLC, LC-MSMS).

I am also interested in PC activity, but so far found nothing on the internet. Phytochelatins act as chelating agents, facilitating cellular intake and decreasing toxicity of heavy metals. I searched for chelation (or complexation) activity on the internet. If there is a thing like "EDTA's chelating activity monitoring" it would be useful to apply similar procedure with PCs. I could not find anything so far.

Another thing came to my mind is to monitor PC activity indirectly. With a controlled experiment, the toxicity of a specific metal on a species (algae or bacteria) with and without the addition of known concentrations of PCs.

This may give clue about detoxifying activity of PCs.

The method requires previous isolation and determination of PCs.

Hope this brainstorming helps you a little bit.

Best regards,

koray