The strong plasmonic chiroptical activities of gold core-DNA-silver shell nanoparticles (NPs) are reported for the first time, using cytosine-rich single-stranded DNA as the template for the guidance of silver shell growth. The anisotropy factor of the optically active NPs at 420 nm reaches 1.93 x 10(-2). Their chiroptical properties are likely induced by the DNA-plasmon interaction and markedly amplified by the strong electromagnetic coupling between the gold core and silver shell.