Recognition-Mediated Assembly of Quantum Dot Polymer Conjugates with Controlled Morphology

We have demonstrated a polymer mediated “bricks and mortar” method for the self-assembly of quantum dots (QDs). This strategy allows QDs to self-assemble into structured aggregates using complementary three-point hydrogen bonding. The resulting nanocomposites have distinct morphologies and inter-particle distances based on the ratio between QDs and polymer. Time resolved photoluminescence measurements showed that the optical properties of the QDs were retained after self-assembly

Engineering functional nanostructures for materials and biological applications

Engineering nanostructures with complete control over the shape, composition, organization of the surface structures, and function remains a major challenge. In my work, I have fabricated nanostructures using functional polymer motifs and nanoparticles (NPs) via supramolecular and non-supramolecular interactions. In one of the approaches to generate nanostructures, I have integrated top-down approaches such as nanoimprint lithography, electron-beam lithography, and photolithography with the self-assembly (bottom-up) of NPs to provide nanostructures with tailored shape and function. In this strategy, I have developed a geometrically assisted orthogonal assembly of nanoparticles onto polymer features at precisely defined locations. This versatile NP functionalization method can be used to fabricate protein resistant patterned surfaces to provide essentially complete control over cellular alignment, making them promising biofunctional structures for cell patterning. In another approach, I have utilized self-assembly of dendrimers and NPs without preformed templates to generate nanostructures that can be used as chemoselective membranes for the separation of small and biomacromolecules

Self-Assembly and Cross-linking of FePt Nanoparticles at Planar and Colloidal Liquid−Liquid Interfaces

Terpyridine thiol functionalized FePt and Au NPs were self-assembled and cross-linked at the liquid−liquid interfaces using Fe(II) metal ion. Complexation of terpyridine with Fe(II) metal ion leads to NP network and affords stable membranes and colloidal shells at the liquid−liquid interfaces

Stable Magnetic Colloidosomes via Click-Mediated Crosslinking of Nanoparticles at Water-Oil Interfaces

Alkyne- and azide-functionalized iron oxide nanoparticles are co-assembled at the water-oil interface and covalently linked using click chemistry under ambient conditions to create magnetic colloidosomes (see image). These colloidosomes possess high stability, size-selective permeability, and are responsive toward external magnetic stimuli

Direct photopatterning of light-activated gold nanoparticles

Photoactivatable gold NPs were patterned via photolithography. In this approach, charge reversal of the ligands on NPs upon UV irradiation induces crosslinking to generate stable NP patterns

Direct patterning of quantum dot nanostructures via electron beam lithography

Patterned quantum dot (QD) nanostructures were prepared by direct electron beam lithography on QD films. Time resolved photoluminescence measurements show that the optical properties of these QDs were retained after cross-linking

Model systems for flavoenzyme activity: intramolecular self-assembly of a flavin derivative via hydrogen bonding and aromatic interactions

We have synthesised a flavin derivative incorporating functionalities that promote intramolecular self-assembly via hydrogen bonding and aromatic interactions

Recognition mediated encapsulation and isolation of flavin-polymer conjugates using dendritic guest moieties

Diaminopyridine dendritic scaffolds encapsulate polymeric flavin via non-covalent interactions and demonstrate isolation of the redox moiety