Unveiling Nanoparticle Dynamics: Our Paper on Optothermal Tweezers Accepted in ACS Nano

We are thrilled to announce that our latest research, "Single Nanoparticle Dynamics in Opto-Thermal Tweezers: Resolving the Temporal Resolution of Depletion Force Trapping", has been accepted for publication in ACS Nano!

In this work, we achieve a milestone by resolving the temporal dynamics of single 40 nm polystyrene nanoparticles in optothermal traps with sub-millisecond resolution. Using time-resolved fluorescence microscopy, we distinguish for the first time between transient localization and stable trapping, a critical ambiguity in previous studies that relied on ensemble averaging.

Our results reveal that residency times exceeding 1 second require PEG concentrations above 7% and IR intensities exceeding 6 mW/µm². Numerical simulations confirm our experimental observations, elucidating the interplay between thermophoresis and diffusiophoresis that governs nanoparticle motion.

This advance deepens our understanding of optothermal trapping mechanisms and paves the way for applications in single nanoparticle studies, nanoscale assembly, and drug delivery systems. We look forward to engaging with the community on these exciting findings!