Publications

Surface plasmon resonance (SPR) is a key technique in developing sensor platforms for clinical diagnostics, drug discovery, food quality, and environmental monitoring applications. While prism-coupled (Kretschmann) SPR remains a "gold-standard" for laboratory work-flows due to easier fabrication, handling and high through put, other configurations such as grating-coupled SPR (GC-SPR) and wave-guide mode SPR are yet to fulfil their technology potential. This work evaluates the technical aspects influencing the performance of GC-SPR and reviews recent progress in the fabrication of such platforms. In principle, the GC-SPR involves the illumination of the plasmonic metal film with periodic gratings to excite the surface plasmons (SP) via diffraction-based phase matching. The real performance of the GC-SPR is, however, heavily influenced by the topography of the grating structures produced via top-down lithography techniques. This review discusses latest in approaches to achieve consistent plasmonic gratings with uniform features and periodicity over a large scale and explores the choice of plasmon-active and substrate material for enhanced performance. The review also provides insights into the different GC-SPR measurement configurations and highlights on opportunities with their potential applications as biosensors with translational capabilities. A review on recent progress in the realization of grating-coupled and wave-guide mode surface plasmon resonance (SPR) platforms which have seen very limited progress toward diagnostics applications in comparison to Kretchmann configured SPR. Sophisticated topography manipulation during large-area nanofabrication, integration of emerging nanomaterials, and machine learning-based data analytics are expected to overcome concurrent challenges toward clinical adoption of grating-coupled SPR in coming years. image

JTD Keywords: Aluminum, Biosensor, Chemical sensor, Compact, Fabrication methods, Gc-spr, Gold, Lase, Lithography, Nanogratings, Performance, Plasmonics, Sensitivity enhancement, Sp, Spr sensor

Organ-on-a-chip (OOC) devices offer new approaches for metabolic disease modeling and drug discovery by providing biologically relevant models of tissues and organs in vitro with a high degree of control over experimental variables for high-content screening applications. Yet, to fully exploit the potential of these platforms, there is a need to interface them with integrated non-labeled sensing modules, capable of monitoring, in situ, their biochemical response to external stimuli, such as stress or drugs. In order to meet this need, we aim here to develop an integrated technology based on coupling a localized surface plasmon resonance (LSPR) sensing module to an OOC device to monitor the insulin in situ secretion in pancreatic islets, a key physiological event that is usually perturbed in metabolic diseases such as type 2 diabetes (T2D). As a proof of concept, we developed a biomimetic islet-on-a-chip (IOC) device composed of mouse pancreatic islets hosted in a cellulose-based scaffold as a novel approach. The IOC was interfaced with a state-of-the-art on-chip LSPR sensing platform to monitor the in situ insulin secretion. The developed platform offers a powerful tool to enable the in situ response study of microtissues to external stimuli for applications such as a drug-screening platform for human models, bypassing animal testing.

JTD Keywords: biosensor, cytoarchitecture, dna hybridization, gelatin, in situ insulin monitoring, langerhans, lspr sensors, microfluidic device, organ-on-a-chip, parallel, platform, scaffold, Animals, Biosensing techniques, Diabetes mellitus, type 2, Drug discovery, Drug evaluation, preclinical, Human pancreatic-islets, Humans, In situ insulin monitoring, Insulin secretion, Insulins, Lab-on-a-chip devices, Lspr sensors, Oligonucleotide array sequence analysis, Organ-on-a-chip, Surface plasmon resonance