Photonic metasurfaces for next-generation biosensors (Conference Presentation) (2018)

New healthcare initiatives including personalized medicine, global health, point-of-care diagnostics require breakthrough developments in biosensing technologies. Unfortunately, current biosensors are time consuming, costly, bulky, require infrastructure and trained laboratory professional, making them unsuitable for disease control and patient care in the field. To address these challenges we employ novel physics and engineering toolkits, such as nanophotonics, nanofabrication, microfluidics. Nanostructured optical metasurfaces based on plasmonics, all-dielectrics or low-dimensional materials are of great interest for biosensor development [1]. They can confine the light below the fundamental diffraction limit and create extremely intense electromagnetic fields in volumes much smaller than the wavelength of light. These features are especially promising for device applications. In this talk I will cover nanoengineered metasurfaces interfaced with biology and chemistry for realization of ultra-sensitive, real-time, label-free and high-throughput biosensors. We exploit metasurfaces for detection of infectious pathogens, disease biomarkers and live cells. For infectious disease applications, we are developing multiplexed nanoplasmonic biosensor arrays for one-step simultaneous detection of bacteria directly from body fluids towards point-of-care devices for efficient population screening and rapid control [2]. With disease biomarkers we are introducing new sensing methodologies for in-vivo protein and lipid analysis under biological conditions [3]. Significantly, our sensor based on surface enhanced infrared spectroscopy is even sensitive to the conformational changes of diseases proteins [4]. Most recently, we presented a new microfluidic-integrated nanoplasmonic biosensor for the study of cell signaling in a label-free and real-time manner. We demonstrated the applicability of our nanobiosensor for long-term monitoring of cytokine secretion from live cancer cells [5]. In parallel, we explore novel two materials for biosensing due to their exceptional opto-electronic properties [6]. In particular by exploiting the unique tunabality of graphene plasmonics with electrostatic gating, we recently demonstrated a dynamically tunable plasmonic Mid-IR biosensor that can extract complete optical refractive index of proteins over a broad spectrum. This talk will cover some of these recent developments. [1] Altug et al. “Nano-optics get practical” Nature Nanotechnology, Vol 10, p. 11-15 (2015). [2] Soler et al. “Multiplexed Nanoplasmonic Biosensor for One-step Detection of Major STD Bacteria in Urine” Biosensors & Bioelectronics, Vol. 94, p. 560-567 (2017). [3] Limaj et al. “Infrared Plasmonic Biosensor for Real-Time and Label-Free Monitoring of Lipid Membranes” Nano Letters, Vol 16, p. 1502–1508 (2016). [4] Etezadi et al. “Nanoplasmonic mid-infrared biosensor for in vitro protein secondary structure detection” Light: Science & Applications, Vol. 6, p. e17029 (2017). [5] Li et al. “Plasmonic nanohole array biosensor for label-free and real-time analysis of live cell secretion” Lab on a Chip, Vol. 17, p. 2208-2217 (2017). [6] D. Rodrigo et al. “Mid-infrared Plasmonic Biosensing with Graphene”, Science, Vol 349, p. 165-168 (2015).