Theoretical Design of a Janus-Nanoparticle-Based Sandwich Assay for Nucleic Acids

Abstract

Nanoparticles exhibit diverse self-assembly attributes and are expected to be applicable under unique settings. For instance, biomolecules can be sandwiched between dimer nanoparticles and detected by surface-enhanced Raman scattering. Controlling the gap between extremely close dimers and stably capturing the target molecule in the gap are crucial aspects of this strategy. Therefore, polymer-tethered nanoparticles (PTNPs), which show promise as high-performance materials that exhibit the attractive features of both NPs and polymers, were targeted in this study to achieve stable biomolecule sensing. Using coarse-grained molecular dynamics simulations, the dependence of the PTNP interactions on the length of the grafted polymer, graft density, and coverage ratio of a hydrophobic tether were examined. The results indicated that the smaller the tether length and graft density, the smaller was the distance between the PTNP surfaces (Rsurf). In contrast, Rsurf decreased as the coverage ratio of the hydrophobic surface (ϕ) increased. The sandwiching probability of the sensing target increased in proportion to the coverage ratio. At high ϕ values, the PTNPs aggregated into three or more particles, which hindered their sensing attributes. These results provide fundamental insight into the sensing applications of NPs and demonstrate the usefulness of PTNPs in sensing biomolecules.

Shear-induced structural and viscosity changes of amphiphilic patchy nanocubes in suspension

“…Colloidal self-assembly has attracted much attention in both science and industry owing to their potential applications, e.g., oil recovery, [1][2][3] drug delivery, [4][5][6] catalysis, [7][8][9] and biosensing. [10][11][12] The collective and enhanced dynamics and properties of these materials arise not only from the chemical nature of the nanoparticles, but also from their complex self-assembled structures. Therefore, it is important to clarify the relationship between the self-assembled structures and the resulting macroscopic properties to produce materials with the desired properties and functionalities.…”