Force-detected Magnetic Resonance Imaging of Influenza Viruses in the Overcoupled Sensor Regime

TL;DR

This paper demonstrates proton nanoMRI of individual influenza viruses using a force-detected magnetic resonance imaging technique with an overcoupled cantilever, addressing challenges of non-contact interactions in sensitive force measurements.

Contribution

It introduces strategies to overcome overcoupling in force-detected MRI and successfully images influenza viruses at the nanoscale.

Findings

Successful proton nanoMRI of individual influenza viruses.

Identification of overcoupling challenges in force-detected MRI.

Strategies to mitigate non-contact interaction effects.

Abstract

Long and thin scanning force cantilevers are sensitive to small forces, but also vulnerable to detrimental non-contact interactions. Here we present an experiment with a cantilever whose spring constant and static deflection are dominated by the interaction between the tip and the surface, a regime that we refer to as ``overcoupled''. The interactions are an obstacle for ultrasensitive measurements like nanoscale magnetic resonance imaging (nanoMRI). We discuss several strategies to overcome the challenges presented by the overcoupling, and demonstrate proton nanoMRI measurements of individual influenza virus particles.