Development of label-free, highly sensitive, miniaturized surface plasmon resonance sensors enables real-time quantification of biomolecule interactions at atomic-levels, desirable for medical diagnostics and which will allow rapid clinical decisions. However, multi-target diagnostic assays require skilled labor, expensive materials, lengthy manual steps, as well as complicated analysis steps. Here, we develop a microfluidic-integrated digital optical disc (DVD) grating as a metasurface, which is coated with titanium-silver-gold (Ti-Ag-Au, 10, 30, and 15nm) for real-time monitoring of biomolecular interactions and binding affinities. Device fabrication process consists of poly (methyl methacrylate) (PMMA) microfluidic channel assembly on nanoplasmonic DVD surface gratings via double side adhesive (DSA) layers. Compared with other nano- and micro-fabrication methods, DVD-based sensor fabrication is relatively simple, cost-effective, and enables large-scale fabrication with minimum efforts. The plasmonic microfluidic chip surface was illuminated with a broadband light source and the normal reflection signal was monitored using a customized optical-setup. Maximum bulk sensitivity (337 nm/RIU) was observed with 30 seconds of etching period and low glycerol concentration (5%, v/v). Red-shifts of peak-wavelength (~16 nm) upon glycerol concentrations were observed as a function of time (seconds). A 0.6 nm peak-wavelength shift was observed in the step of EDC/NHS coupling and continuous protein A/G and G binding resulted in 0.353 ± 0.211 nm and 0.667 ± 0.116 nm (n=3, p<0.05). The presented platform could be potentially applicable to detect and real-time monitor of various biotargets including bacteria, cells, viruses, and proteins.
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