Yes, instead of adding 2 μL of enzyme suspension an alternative is to dilute the enzyme and add a larger volume to the microplate assay.

Dilute the assay buffer 10-fold with distilled water and use this as the diluent to dilute an aliquot of the enzyme suspension also by 10-fold.  Instead of 2 μL, use 20 μL of the diluted enzyme in the microplate assay.

Product Page (Assay Kits)