Nanoparticle assemblies interconnected with DNA can be used to screen for DNA‐binding molecules colorimetrically. The melting temperature of the nanoparticle assembly increases in the presence of strong‐DNA‐binding molecules. Thus, the strength of the DNA binding can be determined by the change in this sharp melting transition, which is observable by a blue‐to‐red color change (see picture).

Amine‐active N‐hydroxysuccinimide‐terminated alkyl thiol templates are generated using parallel dip‐pen nanolithography (DPN) and are used to covalently couple protein A/G. The protein arrays generated (see figure) are used to capture antibodies through affinity binding, while preserving their biological recognition properties. The versatility of the parallel DPN method for making many similar structures in a relatively high‐throughput manner (14 000 dots in 10 min) is described.

A fluorophore‐based bio‐barcode amplification assay that relies on in situ detection of fluorophore‐labeled barcodes attached to polystyrene (PS) microparticles rather than to gold nanoparticles has been developed; the method involves significantly fewer experimental steps and, thus, reduces the time for the assay without losing its ultrahigh sensitivity. The fluorescence image shows PS particles, on which barcode DNA strands labeled with a fluorophore dye (Alexa 647) have been hybridized with the barcode DNA capture strands.

Two-component triblock magnetic nanorods with gold end blocks and nickel interior blocks have been synthesized and used as affinity templates for the simultaneous and efficient separation of a three component protein mixture. The gold blocks were selectively functionalized with 11-amino-1-undecanethiol, and then glutaraldehyde was used to covalently attach nitrostreptavidin to them. His-tagged proteins bind to the nickel block and biotin-tagged proteins bind to the functionalized gold ends, allowing one to separate a mixture of three proteins with a single material. Each surface bound protein can be released selectively using imidazole for the Histagged protein and biotin for the biotinylated protein.