Oligonucleotide selective detection by levitated optomechanics

TL;DR

This paper presents a novel optomechanical method for detecting specific oligonucleotides using silica nanoparticles trapped by laser, analyzing their oscillation spectra to distinguish functionalized particles with high sensitivity.

Contribution

The study introduces a new optical trapping and spectral analysis technique for oligonucleotide detection, combining experimental data with theoretical modeling and machine learning.

Findings

Differences in oscillation frequency and amplitude between functionalized and non-functionalized particles.

Dimensionality reduction and random forest models successfully distinguish particle types.

No visual differences observed in electron microscopy between particle groups.

Abstract

This study examines the detection of oligonucleotide-specific signals in sensitive optomechanical experiments. Silica nanoparticles were functionalized using ZnCl$_2$ and 25-mers of single-stranded deoxyadenosine and deoxythymidine monophosphate which were optically trapped by a 1550 nm wavelength laser in vacuum. In the optical trap, silica nanoparticles behave as harmonic oscillators, and their oscillation frequency and amplitude can be precisely detected by optical interferometry. The data was compared across particle types, revealing differences in frequency, width and amplitude of peaks with respect to motion of the silica nanoparticles which can be explained by a theoretical model. Data obtained from this platform was analyzed by fitting Lorentzian curves to the spectra. Dimensionality reduction detected differences between the functionalized and non-functionalized silica nanoparticles. Random forest modeling provided further evidence that the fitted data were different between the groups. Transmission electron microscopy was carried out, but did not reveal any visual differences between the particle types.