Fine-tuning nanoparticle size by oligo(guanine)n templated synthesis of CdS: an AFM study.

We are presenting a method for modulating the size of CdS nanoparticles by templating their formation with oligo(guanine)n oligomers where n varied from 5 to 20. The variation in template length resulted in observable changes in the size distribution of the CdS nanoparticles. Statistical analysis of AFM images showed a general trend whereby the CdS average height decreased for longer oligoGn and increased for shorter oligoGn. Concomitantly, shorter oligoGn yielded more dispersed populations, while longer oligoGn gave less dispersed populations. This synthetic methodology could be extended to the synthesis of other nanoparticles and even to mixed-metal nanoparticles resulting in a powerful method for fine-tuning size-dependent properties.