Enzyme mediated synthesis of phytochelatin-capped CdS nanocrystals

We reported the enzyme mediated synthesis of CdS nanocrystals by immobilized phytochelatin synthase, which converts glutathione into the metal-binding peptide phytochelatin (PC). Formation of CdS nanocrystals were observed upon the addition of CdCl₂ and Na₂ S with PC as the capping agent. By varying the reaction times, different compositions of PCs (form PC2 to PC3) can be synthesized, resulting in the formation of highly stable nanocrystals with tunable sizes (from 2.0 to 1.6 nm diameter). This approach may be generalized to guide the in vitro self assembly of a wide range of nanocrystals with different compositions and sizes.