Directional Movement of Dendritic Macromolecules on Gradient Surfaces

Abstract

A gradient-driven methodology has been developed to manipulate the movement of dendritic macromolecules. Poly(propyleneimine) dendrimers, labeled with rhodamine B, are attached to glass substrates via multiple imine bonds. The dendrimers are able to move on the surface by the hydrolysis and re-formation of these imine bonds. In the absence of an external stimulus, this random movement results in a two-dimensional diffusion on the substrate. We are able to bias the movement of these nanoparticles by means of an aldehyde gradient on the glass substrate.

Synthesis and characterization of phosphorus-containing dendrimers bearing rhodamine derivatives as terminal groups

“…Due to problems of solubility, the salt 4 could not be grafted on a phosphorus-containing dendrimer, but the neutral rhodamine derivative 3B was successfully grafted as terminal groups. A few papers have reported the synthesis of dendrimers labeled with rhodamine (rhodamine being linked to one or a few terminal functions 13,14 ) but to the best of our knowledge, 5-G 1 is the first example of a dendrimer bearing rhodamine moieties on all terminal groups. Addition of HCl did not damage the structure of the dendrimer, and does not open the spirolactam form of the rhodamine terminal groups (or only some of them).…”

“…Thus, the structure of 3 cannot be the open form 3A but the spirolactam form 3B; this was confirmed by the 13 C NMR signal at δ 65.13 assigned to the spiro-carbon. This result was unexpected but may be interesting for practical synthesis.…”

“…The peptide coupling strategy used previously was successfully applied to afford compound 4, which is dark purple in color and fluorescent as anticipated (Scheme 3). The open form 4A was confirmed by the absence of a 13 C NMR signal at about δ 65 (spiro carbon) and by the signal at δ 167.87 (N-C=O).…”

Surface-Bound Soft Matter Gradients

“…[159][160][161][162] Chemical reactions can drive not only the motion of liquids but also can govern the movement of larger molecules, such as dendrimers. 187 Chang and co-workers recently demonstrated this concept by using amine-terminated dendrimer molecules that were placed onto aldehyde-covered substrates ( Figure 9A). The motility was driven by the ability of the amine group to attach to the aldehyde functionality by imine condensation reaction.…”

Reactive monolayers for surface gradients and biomolecular patterned surfaces

“…Reinhoudt, Meijer and coworkers reported dendrimer motion driven by interfacial reactions on surface chemical gradients prepared using the immersion method. 130 Aldehyde-terminated surface gradients on glass were prepared by gradual immersion of the substrate into solutions of organosilane-based aldehyde. Amine-functionalized dendrimers, labeled with rhodamine B, were printed on such aldehyde gradients and immobilized via formation of multiple imine bonds.…”