Site-specific ligation of DNA-modified gold nanoparticles activated by the restriction enzyme StyI

The site-specific ligation of DNA-modified gold nanoparticles activated by restriction enzyme StyI, for synthesis of nanostructures, was investigated. Two batches of DNA-modified gold nanoparticles with diameter of 15 and 60-80 nm respectively was prepared. The enzyme StyI was incubated with the DNA/gold nanoparticles at 37°C in buffer ( NaCl, tris(hydroxymethy)aminomethane/HCl). After the enzymatic cleavage, reactions were quenched by addition of ethylenediaminetetracetate. Two different sizes of DNA-modified gold nanoparticles activated with enzyme were mixed and mixture was incubated and centrifuged to remove 15-nm particles. Ligation of DNA-modified gold nanoparticles to a gold surface was done using ligation buffer. It was observed that enzymatic activation led spontaneous size segregation between particles for synthesis of nanostructures. Result shows that site-specific ligation of DNA-modified gold nanoparticles is an important method for synthesis of nanostructures.