title: Ultrasensitive and label-free molecular-level detection enabled by light phase control in magnetoplasmonic nanoantennas.
abstract: Systems allowing label-free molecular detection are expected to have enormous impact on biochemical sciences. Research focuses on materials and technologies based on exploiting localized surface plasmon resonances in metallic nanostructures. The reason for this focused attention is their suitability for single-molecule sensing, arising from intrinsically nanoscopic sensing volume and the high sensitivity to the local environment. Here we propose an alternative route, which enables radically improved sensitivity compared with recently reported plasmon-based sensors. Such high sensitivity is achieved by exploiting the control of the phase of light in magnetoplasmonic nanoantennas. We demonstrate a manifold improvement of refractometric sensing figure-of-merit. Most remarkably, we show a raw surface sensitivity (that is, without applying fitting procedures) of two orders of magnitude higher than the current values reported for nanoplasmonic sensors. Such sensitivity corresponds to a mass of ~ 0.8 ag per nanoantenna of polyamide-6.6 (n=1.51), which is representative for a large variety of polymers, peptides and proteins.
authors: CIC nanoGUNE, 20018 Donostia-San Sebastián, Spain.
authors: Nicolò
authors: N
authors: Maccaferri
authors: CIC nanoGUNE, 20018 Donostia-San Sebastián, Spain.
authors: Keith E
authors: KE
authors: Gregorczyk
authors: CIC nanoGUNE, 20018 Donostia-San Sebastián, Spain.
authors: Thales V A G
authors: TV
authors: de Oliveira
authors: NanoSpin, Department of Applied Physics, Aalto University School of Science, 00076 Aalto, Finland.
authors: Mikko
authors: M
authors: Kataja
authors: NanoSpin, Department of Applied Physics, Aalto University School of Science, 00076 Aalto, Finland.
authors: Sebastiaan
authors: S
authors: van Dijken
authors: Department of Applied Physics, Chalmers University of Technology, 41296 Gothenburg, Sweden.
authors: Zhaleh
authors: Z
authors: Pirzadeh
authors: Department of Applied Physics, Chalmers University of Technology, 41296 Gothenburg, Sweden.
authors: Alexandre
authors: A
authors: Dmitriev
authors: 1] Materials Physics, KTH Royal Institute of Technology, Electrum 229, 16440 Kista, Sweden [2] Department of Physics, University of Gothenburg, 41296 Gothenburg, Sweden.
authors: Johan
authors: J
authors: Åkerman
authors: 1] CIC nanoGUNE, 20018 Donostia-San Sebastián, Spain [2] IKERBASQUE, Basque Foundation for Science, 48011 Bilbao, Spain.
authors: Mato
authors: M
authors: Knez
authors: 1] CIC nanoGUNE, 20018 Donostia-San Sebastián, Spain [2] IKERBASQUE, Basque Foundation for Science, 48011 Bilbao, Spain.
authors: Paolo
authors: P
authors: Vavassori
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