Multimode optomechanical weighing of a single nanoparticle

TL;DR

This paper presents a multimode optomechanical sensor capable of weighing individual nanoparticles in real-time under ambient conditions, with potential applications in biological particle analysis.

Contribution

The study introduces a novel multimode optomechanical disk resonator system for real-time weighing of single nanoparticles, including analysis of error sources and potential for biological applications.

Findings

Successfully detected and weighed individual nanoparticles with high precision.

Tracked multiple resonant signals simultaneously for comprehensive analysis.

Discussed methods to evaluate nanoparticle elasticity alongside mass.

Abstract

We demonstrate multimode optomechanical sensing of individual nanoparticles with radius of a hundred of nanometers. A semiconductor optomechanical disk resonator is optically driven and detected under ambient conditions, as nebulized nanoparticles land on it. Multiple mechanical and optical resonant signals of the disk are tracked simultaneously, providing access to several physical informations about the landing analyte in real-time. Thanks to a fast camera registering the time and position of landing, these signals can be employed to weigh each nanoparticle with precision. Sources of error and deviation are discussed and modeled, indicating a path to evaluate the elasticity of the nanoparticles on top of their mere mass. The device is optimized for future investigation of biological particles in the high megadalton range, such as large viruses.