1. pH-conditioning of recognition layers enables single-molecule affinity detections at 10E-20 molar
- Author
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Macchia, Eleonora, Di Franco, Cinzia, Scandurra, Cecilia, Sarcina, Lucia, Piscitelli, Matteo, Catacchio, Michele, Caputo, Mariapia, Bollella, Paolo, Scamarcio, Gaetano, and Torsi, Luisa
- Subjects
Physics - Applied Physics - Abstract
While nucleic-acids can be readily amplified for single-marker detection, a comparable method for proteins assay is currently unavailable. Proteins potentiometric detections at 10-20 molar have been demonstrated, but the mechanism remains elusive. Here, we unveil how pH-conditioning within the trillions of recognition elements densely packed on a millimeter-large surface, enables single protein or DNA selective detections in 0.1 mL of a biofluid. Plasmonic, electronic and surface probing techniques demonstrate that a conformational change, elicited by a single-affinity binding, alters the secondary and tertiary structure of the recognition elements. A phenomenological mechanism foresees that the pH-conditioning initiates a hydrophobization process leading to the formation of a partially aggregated and metastable state that facilitates the amplification spreading. Impact on protein aggregates control and biomarker-based diagnostics, is envisaged.
- Published
- 2024