Surface-functionalized gold nanoparticles mediate bacterial transformation: a nanobiotechnological approach

Transformation of bacteria is an important step in molecular biology. Viral and non-virus-based gene delivery techniques, including chemical/biological and physical approaches, have been applied to bacterial, mammalian and plant cells. E. coli is not competent to take up DNA; hence, different methods are used to incorporate plasmid DNA. A novel method has been developed using glutathione-functionalized gold nanoparticles to mediate transformation of plasmid DNA (pUC19) into E. coli DH5α that does not require the preparation of competent cells. The glutathione-functionalized gold nanoparticles acted as a vector and facilitated the entry of DNA into the host cell. The method also gave a higher transformation efficiency (4.2 × 10(7)/μg DNA) compared to 2.3 × 10(5)/μg DNA using the conventional CaCl2-mediated method. It was also non-toxic to the bacterium making it suitable for biotechnological applications.