Mo6S3I6–Au composites: Synthesis, conductance, and applications

A single-step, premixing method was used to directly deposit gold nanoparticles on Mo6S3I6 (MSI) molecular wire bundles. Gold nanoparticles with different sizes and densities were coated on the MSI by changing the concentration of the gold containing salt, HAuCl4. TEM, SEM, and EDX characterization showed deposition of gold nanoparticles on the MSI nanowire surface. The electrical resistance of these MSI–Au composites was more than 100 times lower than that for pure MSI, and was mainly dependent on the density of the deposited gold nanoparticles. Furthermore, we immobilized thiol group-labeled oligonucleotide on the composites and then hybridized with a fully matched sequence. The resistance of the MSI–Au composites increased during the thiol step, while it decreased by hybridizing, due to the conductance difference between single- and double-stranded DNA chains. These results indicate that this new kind of MSI–Au composite could be used as a platform for different applications, including biosensors.

Graphical abstractMo6S3I6–Au nanocomposites were synthesized with tunable gold nanoparticle sizes and densities with a one-step method, leading to different electric properties. DNA-mediated conductance changes of Mo6S3I6–Au networks suggest the application of Mo6S3I6–Au nanocomposites in biosensing.Figure optionsDownload full-size imageDownload high-quality image (64 K)Download as PowerPoint slide