In Situ Organization of Gold Nanorods on Mixed Self-Assembled-Monolayer Substrates

A method is described for assembling gold nanorods, end‐to‐end, into long chains attached on top of a mixed self‐assembled monolayer that has been functionalized with streptavidin. Methods to prepare chains of nanorods in colloidal suspension have been reported by others, but our protocol offers a way to directly form such structures on a substrate. The rods are spaced ≈5 nm apart in the resulting chains, which extend for over a micrometer in length. The assembly and morphology of the nanorod structures were characterized by surface plasmon resonance spectroscopy, as well as by scanning electron microscopy and scanning probe microscopy. Structures of this type could conceivably serve as plasmonic waveguides in future nanodevices. Chain‐link nanorods: Gold nanorods can be assembled end‐to‐end into long chains attached to the upper surface of a substrate functionalized with a two‐component, self‐assembled monolayer (see the AFM image). The protocol offers a way to form chains of nanorods directly on a substrate. The rods are spaced about 5 nm apart in the chains, which extend for over a micrometer in length.