Plasmonics is expected to make a tremendous impact in the field of life sciences, with applications in bioimaging, biosensing, targeted delivery and externally-triggered locoregional therapy. Plasmonic biosensors are considered to be highly promising for the development of simple, portable, sensitive, on-chip biodiagnostics for resource-limited settings such as at-home care, rural clinics, developing countries with low and moderate incomes and battle-field. While there has been a tremendous progress in the rational design of nanotransducers with high sensitivity and the development of hand-held read-out devices, the translation of these biosensors to resource-limited settings is hindered by the poor thermal, chemical, and environmental stability of the biorecogntion elements. “Cold-chain”, which is employed in the affluent parts of the world for reagent transport, storage, and handling, is expensive (capital cost of freezers, recurring cost of liquid nitrogen), environmentally unfriendly, and simply not feasible in resource-limited settings where electricity and refrigeration are not reliable or even available. Degradation of the sensitive reagents and biodiagnostic chips outside the cold-chain, compromises analytical validity, preventing accurate and timely diagnosis. We will present a novel class of plasmonic biosensors that rely artificial antibodies or peptide recognition elements with excellent thermal and chemical stability. In addition, we have recently introduced silk and metal-organic frameworks as protective coatings to stabilize natural antibodies bound to nanotransducers against thermal denaturation and loss of biorecognition. This multi-pronged approach overcomes the poor stability of existing plasmonic biosensors and takes them closer to real-world applications in resource-limited settings.
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