Photonic Integrated Circuit And Protein Catalyzed Capture Biosensor For Sensing Interleuken-6 in Serum

Wearable sensors for the continuous monitoring of biomarkers are increasingly needed for an array of applications from personalized medicine to tracking sports performance and addressing medical emergencies. The introduction of continuous glucose monitoring (CGM) sensors illustrated the impact of a single-target sensor on diagnosis, treatment and management of a disease. Wearable sensors require a small form factor and mobility as well as resilience to drastic changes in temperature and long-term exposure to the elements. Thus, there is a need for additional shelf-stable sensors for physiologically relevant small molecules and proteins. Although there are many up-and-coming sensor methodologies for protein detection, the majority rely on antibodies. These methods require refrigeration and a cold-chain for optimal quality, making them logistically challenging and demanding of energy/resources. Here, we developed a shelf stable biosensor for proteins using photonic integrated circuits (PIC) and protein catalyzed capture (PCC) peptides. PCCs are computationally designed short peptide sequences that act as synthetic antibodies with temperature stability up to 90C. This makes them ideal candidates for a protein biosensor recognition element in extreme and dynamic environments. PICs are complete photonic systems on chip and are fabricated using CMOS techniques with both active and passive electro-optical components. They are a mass manufacturable (low cost), lightweight (grams) transducer with a small footprint (millimeter) and low power requirements (low SWaP-C). Together the PIC transducer and PCC recognition element create a fieldable, shelf stable sensor for the continuous monitoring of an array of biomarker targets. Here, we show a PCC peptide selective to interleukin-6 (IL-6) for the on-chip monitoring of IL-6 levels in serum.