Oh, my
stars and hexagons! DNA code shapes gold nanoparticles
“We
wondered whether different combinations of DNA sequences could constitute
‘genetic codes’ to direct the nanomaterial synthesis in a way similar to their
direction of protein synthesis,” said Zidong Wang, a recent graduate of Lu’s
group and the first author of the paper.
Gold
nanoparticles are made by sewing tiny gold seeds in a solution of gold salt.
Particles grow as gold in the salt solution deposits onto the seeds. Lu’s group
incubated the gold seeds with short segments of DNA before adding the salt
solution, causing the particles to grow into various shapes determined by the
genetic code of the DNA.
The DNA
alphabet comprises four letters: A, T, G and C. The term genetic code refers to
the sequence of these letters, called bases. The four bases and their
combinations can bind differently with facets of gold nanoseeds and direct the
nanoseeds’ growth pathways, resulting in different shapes.