Luminescent Cadmium Sulfide Nanochains Templated on Unfixed Deoxyribonucleic Acid and Their Fractal Alignment by Droplet Dewetting

A method for self-assembly of cadmium sulfide (CdS) nanochains (NCs) was proposed by direct deposition of CdS on unfixed DNA (DNA) template with 2-aminoethanethiol as a capping agent. The fractal alignment of CdS NCs on meniscus was then addressed utilizing droplet dewetting. The morphologies of CdS NCs were characterized with transmission electron microscopy, and their luminescent behaviors were investigated by photoluminescence and electrogenerated chemiluminescence (ECL). The presence of DNA scaffolds resulted in perfect surface status and efficient ECL of CdS NCs. The ECL mechanism and the heterogeneous nucleation process were also discussed. Adjusting the molar ratio of DNA to cadmium cation for synthesis could efficiently control the eventual NCs fractal on meniscus during the droplet dewetting and the properties of obtained NCs. The preferred pattern was formed at the molar ratio of 1:1. The present strategy provides a new way to synthesize and align nanowire devices without fixation of DNA and presynthesis of quantum dots (QDs) and has a potential applicability in pattern manufacture in natural way.