Ultrasensitive and label-free molecular-level detection enabled by light phase control in magnetoplasmonic nanoantennas
Journal article, 2015

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 similar to 0.8 ag per nanoantenna of polyamide-6.6 (n = 1.51), which is representative for a large variety of polymers, peptides and proteins.


N. Maccaferri


K. E. Gregorczyk


Tvag de Oliveira


M. Kataja

Aalto University

S. van Dijken

Aalto University

Zhaleh Pirzadeh Irannezhad

Chalmers, Applied Physics, Bionanophotonics

Alexander Dmitriev

Chalmers, Applied Physics, Bionanophotonics

Johan Åkerman

Royal Institute of Technology (KTH)

University of Gothenburg

M. Knez

Basque Foundation for Science (Ikerbasque)

Paolo Vavassori


Basque Foundation for Science (Ikerbasque)

Nature Communications

2041-1723 (ISSN)

Vol. 6 6150

Subject Categories

Physical Sciences



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