Advancements in nanotechnology have transformed our ability to characterize and manipulate biological systems and enabled significant progress in the studies of biology and medicine. An exciting area of growth is the development of strategies to non-destructively interface artificial materials with biological membranes, specifically with bioinspired technologies that mimic the endogenous membrane architecture. Previous work in developing biomimetic stealth probes has demonstrated the ability to recreate the plasma membrane’s hydrophilic-hydrophobic-hydrophilic architecture by self-assembling hydrophobic molecules onto a thin band of gold sandwiched between two layers of chromium. This unique interfacial architecture enabled the formation of high-strength interfaces between the probe and the plasma membrane. Building upon this work, this thesis aimed to create multilayered Au and Cr nanoparticles capable of spontaneous and non-destructive integration into cell membranes and function as inorganic gap junctions for cellular sensing, molecular drug delivery, and more.
This thesis reports on the design and fabrication of doughnut-shaped Au and Cr nanoparticles measuring approximately 200 nm in diameter using electron beam lithography. By utilizing the dual-toned behavior of polymethyl methacrylate resists, sub-50 nm diameter centrally located holes spanning the full thickness of the nanoparticles were created. During nanoparticle release from the fabrication substrate, discovery of unexpected gold-catalyzed etching of silicon in fluorine-based plasma prompted investigation into the phenomenon termed ‘metal-assisted plasma etching (MAPE)’. Experiments systematically examined the effect of the catalyst architecture and the silicon substrate in MAPE and established a proposed mechanism for this interfacial-driven process. Lastly, colloidal patterning and nanoimprint lithography were explored as alternative fabrication methods for nanoparticle fabrication. The work presented in this thesis introduces the biomimetic nanoparticle as a novel platform technology and represents significant progress toward realizing full integration of artificial structures into biological membranes.