Development of Site-selective Functionalization at Nanoscale

Introduction & context

Diverse biosensing techniques have been actively developed over the last decades, utilizing nanofabrication for electronic and photonic sensors. At imec, we are developing such state-of-the-art biosensors including solid-state nanopore devices for single-molecule DNA/protein sequencing, on-chip super-resolution microscopy for multi-omics imaging, and nano-scale FET (field-effect transistor) devices for single-biomolecule detection, just to name a few. In particular, the ability of site-selective biomolecule functionalization at submicron-scale is highly desirable for increasing the sensitivity and specificity of biosensors. It is also beneficial to be compatible with the CMOS chip fabrication environment and hence gives a direct route towards high-volume manufacturing. However, many existing submicron-scale selective functionalization methods still lack either scalability or CMOS compatibility due to the use of low-throughput patterning approaches or non-compatible materials. Therefore, imec has been actively developing various CMOS-compatible site-selective surface functionalization methods for controlled biomolecule placement at submicron-scale, via wafer-level processing.

In this project, the student will contribute towards pushing the limits of the nanoscale surface patterning of biomolecules. The student will first perform material characterizations of the nano-patterned semiconductor chips supplied from imec’s state-of-the-art cleanrooms, followed by applying organo-silane self-assembled monolayer (SAM) coatings and site-selective immobilization of biomolecules using the methods established in our laboratories. For example, SAM coatings include azide layer for biomolecule immobilization via click-chemistry (Nobel prize in 2022) and polyethylene oxide layer for antifouling of biomolecules. Further, other additional methods (e.g., DNA origami nanostructures, 2D materials, lipid layers) can be also explored. Such various types of coatings can be patterned on a single chip surface at nano-scale with a high-precision using the imec-developed sacrificial-layer lithography approach. The surface composition and morphology after each process will be investigated by a set of complementary characterization methods including infrared spectroscopy, ellipsometry, contact angle, and microscopy measurements. The proper attachment of biomolecules on the flat surface or the 3D nano-structures will be evaluated by diverse techniques such as confocal fluorescence microscopy, scanning electron microscopy, and atomic force microscopy. We will explore novel ideas for nano-patterning materials, surface coating chemistries, biomolecule immobilization strategies, and surface characterization methods.  

Your main responsibilities

• Application and optimization of site-selective biofunctionalization protocol
• Characterization of diverse self-assembled monolayers
• Characterization of diverse selectively immobilized biomolecules
• Explore improved surface coating and characterization strategies for specific binding and antifouling of diverse biomolecules

Competences expected

• Background in (Bio)Chemistry, (Bio)Nanotechnology, (Bio)Physics, Chemical Engineering, or Materials Engineering