Close proximity real-time photonic sensing of single-cell biomolecule secretion
Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
We develop a novel concept for photonic sensing of single-cell biomolecule secretion. The sensing technique is based on biomolecule detection with a waveguide-based photonic ring resonator biosensor.
Biomolecule secretion plays an important role in cell communication. Defects lead to a wide range of diseases, and thus biomolecule secretion is commonly used as a marker for disease detection. However, there is no tool capable of detecting biomolecule secretion at the single cell level. Such a tool is of key importance for the development of several elds of medicine and biology, along with new industries such as bioproduction.
We use photonic sensing to develop this tool. Photonic sensing allows sensor miniaturization reaching the cell size, low detection limits, and short detection times. Moreover, simple fabrication and scalability enable mass production in dense arrays at low cost.
In this Master of Science Thesis, we focus our work on two main fronts: integration of microfluidics on photonics, and cell-handling.
First, we present a novel method for the integration of polymer microfluidics with photonic silicon sensors, compatible with wafer scale production methods. The current polymeric solution (PDMS) presents drawbacks such as large wafer area consumption, and limited compatibility with bonding onto biofunctionalized surfaces. We fabricated a micro uidics layer in a single step in the recently introduced OSTE polymer, and dry-bonded it to a photonic silicon sensor. This integration method can match the microfluidics to the size scale of current photonic silicon sensors. To demonstrate the integration concept, we report refractive index measurements with a grating coupled Mach-Zehnder interferometer sensor chip. Moreover, we report refractive index measurements with a grating coupled photonic ring resonator sensor chip fabricated by these means. We report a Q-factor of 17000, and a sensitivity of 50 nm/RIU for this sensor.
Second, after running biocompatibility experiments on cell growth on 5 formulations of OSTE polymers, we demonstrate cell trapping in molded OSTE polymer traps. Human Embryonic Kidney cell (HEK) trapping with microfluidic chips of OSTE, fabricated in a single step process and drybonded to glass chips, is reported.
Place, publisher, year, edition, pages
2013. , 107 p.
, XR-EE-MST, 2013:001
photonic, sensing, biomolecule, microfluidics, ring resonator, silicon, refractive index, OSTE
Electrical Engineering, Electronic Engineering, Information Engineering
IdentifiersURN: urn:nbn:se:kth:diva-140648OAI: oai:DiVA.org:kth-140648DiVA: diva2:692174
Subject / course
2013-03-12, Q2, Osquldas väg 10, Stockholm, 11:32 (English)
Gylfason, Kristinn B., Dr.
Sohlström, Hans, docent